diff --git a/NEWS b/NEWS
index dd0bd93f..7e78180e 100644
--- a/NEWS
+++ b/NEWS
@@ -1,9 +1,15 @@
 1.9.11.dev0
- * #996: Fix the "create" action to omit the repository label prefix from Borg's output when
-   databases are enabled.
  * #795: Add credential loading from file, KeePassXC, and Docker/Podman secrets. See the
    documentation for more information:
    https://torsion.org/borgmatic/docs/how-to/provide-your-passwords/
+ * #996: Fix the "create" action to omit the repository label prefix from Borg's output when
+   databases are enabled.
+ * #1001: For the ZFS, Btrfs, and LVM hooks, only make snapshots for root patterns that come from
+   a borgmatic configuration option (e.g. "source_directories")—not from other hooks within
+   borgmatic.
+ * #1001: Fix a ZFS/LVM error due to colliding snapshot mount points for nested datasets or logical
+   volumes.
+ * #1001: Don't try to snapshot ZFS datasets that have the "canmount=off" property.
  * Send the "encryption_passphrase" option to Borg via an anonymous pipe, which is more secure than
    using an environment variable.
  * Fix another error in the Btrfs hook when a subvolume mounted at "/" is configured in borgmatic's
diff --git a/borgmatic/actions/create.py b/borgmatic/actions/create.py
index ab7815e4..dede448a 100644
--- a/borgmatic/actions/create.py
+++ b/borgmatic/actions/create.py
@@ -36,6 +36,7 @@ def parse_pattern(pattern_line, default_style=borgmatic.borg.pattern.Pattern_sty
         path,
         borgmatic.borg.pattern.Pattern_type(pattern_type),
         borgmatic.borg.pattern.Pattern_style(pattern_style),
+        source=borgmatic.borg.pattern.Pattern_source.CONFIG,
     )
 
 
@@ -51,7 +52,9 @@ def collect_patterns(config):
     try:
         return (
             tuple(
-                borgmatic.borg.pattern.Pattern(source_directory)
+                borgmatic.borg.pattern.Pattern(
+                    source_directory, source=borgmatic.borg.pattern.Pattern_source.CONFIG
+                )
                 for source_directory in config.get('source_directories', ())
             )
             + tuple(
@@ -144,6 +147,7 @@ def expand_patterns(patterns, working_directory=None, skip_paths=None):
                         pattern.type,
                         pattern.style,
                         pattern.device,
+                        pattern.source,
                     )
                     for expanded_path in expand_directory(pattern.path, working_directory)
                 )
@@ -178,6 +182,7 @@ def device_map_patterns(patterns, working_directory=None):
                 and os.path.exists(full_path)
                 else None
             ),
+            source=pattern.source,
         )
         for pattern in patterns
         for full_path in (os.path.join(working_directory or '', pattern.path),)
diff --git a/borgmatic/borg/create.py b/borgmatic/borg/create.py
index 9436afd4..aea0cbc8 100644
--- a/borgmatic/borg/create.py
+++ b/borgmatic/borg/create.py
@@ -132,9 +132,12 @@ def collect_special_file_paths(
     used.
 
     Skip looking for special files in the given borgmatic runtime directory, as borgmatic creates
-    its own special files there for database dumps. And if the borgmatic runtime directory is
-    configured to be excluded from the files Borg backs up, error, because this means Borg won't be
-    able to consume any database dumps and therefore borgmatic will hang.
+    its own special files there for database dumps and we don't want those omitted.
+
+    Additionally, if the borgmatic runtime directory is not contained somewhere in the files Borg
+    plans to backup, that means the user must have excluded the runtime directory (e.g. via
+    "exclude_patterns" or similar). Therefore, raise, because this means Borg won't be able to
+    consume any database dumps and therefore borgmatic will hang when it tries to do so.
     '''
     # Omit "--exclude-nodump" from the Borg dry run command, because that flag causes Borg to open
     # files including any named pipe we've created.
@@ -148,25 +151,33 @@ def collect_special_file_paths(
         borg_exit_codes=config.get('borg_exit_codes'),
     )
 
+    # These are all the individual files that Borg is planning to backup as determined by the Borg
+    # create dry run above.
     paths = tuple(
         path_line.split(' ', 1)[1]
         for path_line in paths_output.split('\n')
         if path_line and path_line.startswith('- ') or path_line.startswith('+ ')
     )
-    skip_paths = {}
+
+    # These are the subset of those files that contain the borgmatic runtime directory.
+    paths_containing_runtime_directory = {}
 
     if os.path.exists(borgmatic_runtime_directory):
-        skip_paths = {
+        paths_containing_runtime_directory = {
             path for path in paths if any_parent_directories(path, (borgmatic_runtime_directory,))
         }
 
-        if not skip_paths and not dry_run:
+        # If no paths to backup contain the runtime directory, it must've been excluded.
+        if not paths_containing_runtime_directory and not dry_run:
             raise ValueError(
                 f'The runtime directory {os.path.normpath(borgmatic_runtime_directory)} overlaps with the configured excludes or patterns with excludes. Please ensure the runtime directory is not excluded.'
             )
 
     return tuple(
-        path for path in paths if special_file(path, working_directory) if path not in skip_paths
+        path
+        for path in paths
+        if special_file(path, working_directory)
+        if path not in paths_containing_runtime_directory
     )
 
 
@@ -325,6 +336,7 @@ def make_base_create_command(
                         special_file_path,
                         borgmatic.borg.pattern.Pattern_type.NO_RECURSE,
                         borgmatic.borg.pattern.Pattern_style.FNMATCH,
+                        source=borgmatic.borg.pattern.Pattern_source.INTERNAL,
                     )
                     for special_file_path in special_file_paths
                 ),
diff --git a/borgmatic/borg/pattern.py b/borgmatic/borg/pattern.py
index be57bc0e..dfce7c3b 100644
--- a/borgmatic/borg/pattern.py
+++ b/borgmatic/borg/pattern.py
@@ -20,12 +20,31 @@ class Pattern_style(enum.Enum):
     PATH_FULL_MATCH = 'pf'
 
 
+class Pattern_source(enum.Enum):
+    '''
+    Where the pattern came from within borgmatic. This is important because certain use cases (like
+    filesystem snapshotting) only want to consider patterns that the user actually put in a
+    configuration file and not patterns from other sources.
+    '''
+
+    # The pattern is from a borgmatic configuration option, e.g. listed in "source_directories".
+    CONFIG = 'config'
+
+    # The pattern is generated internally within borgmatic, e.g. for special file excludes.
+    INTERNAL = 'internal'
+
+    # The pattern originates from within a borgmatic hook, e.g. a database hook that adds its dump
+    # directory.
+    HOOK = 'hook'
+
+
 Pattern = collections.namedtuple(
     'Pattern',
-    ('path', 'type', 'style', 'device'),
+    ('path', 'type', 'style', 'device', 'source'),
     defaults=(
         Pattern_type.ROOT,
         Pattern_style.NONE,
         None,
+        Pattern_source.HOOK,
     ),
 )
diff --git a/borgmatic/hooks/data_source/bootstrap.py b/borgmatic/hooks/data_source/bootstrap.py
index 67d75421..fe779f0e 100644
--- a/borgmatic/hooks/data_source/bootstrap.py
+++ b/borgmatic/hooks/data_source/bootstrap.py
@@ -55,9 +55,17 @@ def dump_data_sources(
             manifest_file,
         )
 
-    patterns.extend(borgmatic.borg.pattern.Pattern(config_path) for config_path in config_paths)
+    patterns.extend(
+        borgmatic.borg.pattern.Pattern(
+            config_path, source=borgmatic.borg.pattern.Pattern_source.HOOK
+        )
+        for config_path in config_paths
+    )
     patterns.append(
-        borgmatic.borg.pattern.Pattern(os.path.join(borgmatic_runtime_directory, 'bootstrap'))
+        borgmatic.borg.pattern.Pattern(
+            os.path.join(borgmatic_runtime_directory, 'bootstrap'),
+            source=borgmatic.borg.pattern.Pattern_source.HOOK,
+        )
     )
 
     return []
diff --git a/borgmatic/hooks/data_source/btrfs.py b/borgmatic/hooks/data_source/btrfs.py
index 2971aed8..ec6d33df 100644
--- a/borgmatic/hooks/data_source/btrfs.py
+++ b/borgmatic/hooks/data_source/btrfs.py
@@ -54,7 +54,9 @@ def get_subvolumes(btrfs_command, findmnt_command, patterns=None):
     between the current Btrfs filesystem and subvolume mount points and the paths of any patterns.
     The idea is that these pattern paths represent the requested subvolumes to snapshot.
 
-    If patterns is None, then return all subvolumes, sorted by path.
+    Only include subvolumes that contain at least one root pattern sourced from borgmatic
+    configuration (as opposed to generated elsewhere in borgmatic). But if patterns is None, then
+    return all subvolumes instead, sorted by path.
 
     Return the result as a sequence of matching subvolume mount points.
     '''
@@ -73,7 +75,12 @@ def get_subvolumes(btrfs_command, findmnt_command, patterns=None):
                     mount_point, candidate_patterns
                 ),
             )
-            if patterns is None or contained_patterns
+            if patterns is None
+            or any(
+                pattern.type == borgmatic.borg.pattern.Pattern_type.ROOT
+                and pattern.source == borgmatic.borg.pattern.Pattern_source.CONFIG
+                for pattern in contained_patterns
+            )
         )
 
     return tuple(sorted(subvolumes, key=lambda subvolume: subvolume.path))
@@ -121,6 +128,7 @@ def make_snapshot_exclude_pattern(subvolume_path):  # pragma: no cover
         ),
         borgmatic.borg.pattern.Pattern_type.NO_RECURSE,
         borgmatic.borg.pattern.Pattern_style.FNMATCH,
+        source=borgmatic.borg.pattern.Pattern_source.HOOK,
     )
 
 
@@ -153,6 +161,7 @@ def make_borg_snapshot_pattern(subvolume_path, pattern):
         pattern.type,
         pattern.style,
         pattern.device,
+        source=borgmatic.borg.pattern.Pattern_source.HOOK,
     )
 
 
@@ -198,7 +207,8 @@ def dump_data_sources(
     dry_run_label = ' (dry run; not actually snapshotting anything)' if dry_run else ''
     logger.info(f'Snapshotting Btrfs subvolumes{dry_run_label}')
 
-    # Based on the configured patterns, determine Btrfs subvolumes to backup.
+    # Based on the configured patterns, determine Btrfs subvolumes to backup. Only consider those
+    # patterns that came from actual user configuration (as opposed to, say, other hooks).
     btrfs_command = hook_config.get('btrfs_command', 'btrfs')
     findmnt_command = hook_config.get('findmnt_command', 'findmnt')
     subvolumes = get_subvolumes(btrfs_command, findmnt_command, patterns)
diff --git a/borgmatic/hooks/data_source/lvm.py b/borgmatic/hooks/data_source/lvm.py
index 8436d0f6..11cd1c09 100644
--- a/borgmatic/hooks/data_source/lvm.py
+++ b/borgmatic/hooks/data_source/lvm.py
@@ -1,5 +1,6 @@
 import collections
 import glob
+import hashlib
 import json
 import logging
 import os
@@ -33,7 +34,9 @@ def get_logical_volumes(lsblk_command, patterns=None):
     between the current LVM logical volume mount points and the paths of any patterns. The idea is
     that these pattern paths represent the requested logical volumes to snapshot.
 
-    If patterns is None, include all logical volume mounts points, not just those in patterns.
+    Only include logical volumes that contain at least one root pattern sourced from borgmatic
+    configuration (as opposed to generated elsewhere in borgmatic). But if patterns is None, include
+    all logical volume mounts points instead, not just those in patterns.
 
     Return the result as a sequence of Logical_volume instances.
     '''
@@ -72,7 +75,12 @@ def get_logical_volumes(lsblk_command, patterns=None):
                     device['mountpoint'], candidate_patterns
                 ),
             )
-            if not patterns or contained_patterns
+            if not patterns
+            or any(
+                pattern.type == borgmatic.borg.pattern.Pattern_type.ROOT
+                and pattern.source == borgmatic.borg.pattern.Pattern_source.CONFIG
+                for pattern in contained_patterns
+            )
         )
     except KeyError as error:
         raise ValueError(f'Invalid {lsblk_command} output: Missing key "{error}"')
@@ -124,10 +132,14 @@ def mount_snapshot(mount_command, snapshot_device, snapshot_mount_path):  # prag
     )
 
 
-def make_borg_snapshot_pattern(pattern, normalized_runtime_directory):
+MOUNT_POINT_HASH_LENGTH = 10
+
+
+def make_borg_snapshot_pattern(pattern, logical_volume, normalized_runtime_directory):
     '''
-    Given a Borg pattern as a borgmatic.borg.pattern.Pattern instance, return a new Pattern with its
-    path rewritten to be in a snapshot directory based on the given runtime directory.
+    Given a Borg pattern as a borgmatic.borg.pattern.Pattern instance and a Logical_volume
+    containing it, return a new Pattern with its path rewritten to be in a snapshot directory based
+    on both the given runtime directory and the given Logical_volume's mount point.
 
     Move any initial caret in a regular expression pattern path to the beginning, so as not to break
     the regular expression.
@@ -142,6 +154,13 @@ def make_borg_snapshot_pattern(pattern, normalized_runtime_directory):
     rewritten_path = initial_caret + os.path.join(
         normalized_runtime_directory,
         'lvm_snapshots',
+        # Including this hash prevents conflicts between snapshot patterns for different logical
+        # volumes. For instance, without this, snapshotting a logical volume at /var and another at
+        # /var/spool would result in overlapping snapshot patterns and therefore colliding mount
+        # attempts.
+        hashlib.shake_256(logical_volume.mount_point.encode('utf-8')).hexdigest(
+            MOUNT_POINT_HASH_LENGTH
+        ),
         '.',  # Borg 1.4+ "slashdot" hack.
         # Included so that the source directory ends up in the Borg archive at its "original" path.
         pattern.path.lstrip('^').lstrip(os.path.sep),
@@ -152,6 +171,7 @@ def make_borg_snapshot_pattern(pattern, normalized_runtime_directory):
         pattern.type,
         pattern.style,
         pattern.device,
+        source=borgmatic.borg.pattern.Pattern_source.HOOK,
     )
 
 
@@ -180,7 +200,8 @@ def dump_data_sources(
     dry_run_label = ' (dry run; not actually snapshotting anything)' if dry_run else ''
     logger.info(f'Snapshotting LVM logical volumes{dry_run_label}')
 
-    # List logical volumes to get their mount points.
+    # List logical volumes to get their mount points, but only consider those patterns that came
+    # from actual user configuration (as opposed to, say, other hooks).
     lsblk_command = hook_config.get('lsblk_command', 'lsblk')
     requested_logical_volumes = get_logical_volumes(lsblk_command, patterns)
 
@@ -218,6 +239,9 @@ def dump_data_sources(
         snapshot_mount_path = os.path.join(
             normalized_runtime_directory,
             'lvm_snapshots',
+            hashlib.shake_256(logical_volume.mount_point.encode('utf-8')).hexdigest(
+                MOUNT_POINT_HASH_LENGTH
+            ),
             logical_volume.mount_point.lstrip(os.path.sep),
         )
 
@@ -233,7 +257,9 @@ def dump_data_sources(
         )
 
         for pattern in logical_volume.contained_patterns:
-            snapshot_pattern = make_borg_snapshot_pattern(pattern, normalized_runtime_directory)
+            snapshot_pattern = make_borg_snapshot_pattern(
+                pattern, logical_volume, normalized_runtime_directory
+            )
 
             # Attempt to update the pattern in place, since pattern order matters to Borg.
             try:
@@ -337,6 +363,7 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
             os.path.normpath(borgmatic_runtime_directory),
         ),
         'lvm_snapshots',
+        '*',
     )
     logger.debug(f'Looking for snapshots to remove in {snapshots_glob}{dry_run_label}')
     umount_command = hook_config.get('umount_command', 'umount')
@@ -349,7 +376,10 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
             snapshot_mount_path = os.path.join(
                 snapshots_directory, logical_volume.mount_point.lstrip(os.path.sep)
             )
-            if not os.path.isdir(snapshot_mount_path):
+
+            # If the snapshot mount path is empty, this is probably just a "shadow" of a nested
+            # logical volume and therefore there's nothing to unmount.
+            if not os.path.isdir(snapshot_mount_path) or not os.listdir(snapshot_mount_path):
                 continue
 
             # This might fail if the directory is already mounted, but we swallow errors here since
@@ -374,7 +404,7 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
                 return
             except subprocess.CalledProcessError as error:
                 logger.debug(error)
-                return
+                continue
 
         if not dry_run:
             shutil.rmtree(snapshots_directory)
diff --git a/borgmatic/hooks/data_source/mariadb.py b/borgmatic/hooks/data_source/mariadb.py
index 727932ee..b992a944 100644
--- a/borgmatic/hooks/data_source/mariadb.py
+++ b/borgmatic/hooks/data_source/mariadb.py
@@ -216,7 +216,8 @@ def dump_data_sources(
     if not dry_run:
         patterns.append(
             borgmatic.borg.pattern.Pattern(
-                os.path.join(borgmatic_runtime_directory, 'mariadb_databases')
+                os.path.join(borgmatic_runtime_directory, 'mariadb_databases'),
+                source=borgmatic.borg.pattern.Pattern_source.HOOK,
             )
         )
 
diff --git a/borgmatic/hooks/data_source/mongodb.py b/borgmatic/hooks/data_source/mongodb.py
index 2148f009..59811101 100644
--- a/borgmatic/hooks/data_source/mongodb.py
+++ b/borgmatic/hooks/data_source/mongodb.py
@@ -81,7 +81,8 @@ def dump_data_sources(
     if not dry_run:
         patterns.append(
             borgmatic.borg.pattern.Pattern(
-                os.path.join(borgmatic_runtime_directory, 'mongodb_databases')
+                os.path.join(borgmatic_runtime_directory, 'mongodb_databases'),
+                source=borgmatic.borg.pattern.Pattern_source.HOOK,
             )
         )
 
diff --git a/borgmatic/hooks/data_source/mysql.py b/borgmatic/hooks/data_source/mysql.py
index ffa2bc3f..3172edbb 100644
--- a/borgmatic/hooks/data_source/mysql.py
+++ b/borgmatic/hooks/data_source/mysql.py
@@ -215,7 +215,8 @@ def dump_data_sources(
     if not dry_run:
         patterns.append(
             borgmatic.borg.pattern.Pattern(
-                os.path.join(borgmatic_runtime_directory, 'mysql_databases')
+                os.path.join(borgmatic_runtime_directory, 'mysql_databases'),
+                source=borgmatic.borg.pattern.Pattern_source.HOOK,
             )
         )
 
diff --git a/borgmatic/hooks/data_source/postgresql.py b/borgmatic/hooks/data_source/postgresql.py
index 8cf17518..559cc4b8 100644
--- a/borgmatic/hooks/data_source/postgresql.py
+++ b/borgmatic/hooks/data_source/postgresql.py
@@ -239,7 +239,8 @@ def dump_data_sources(
     if not dry_run:
         patterns.append(
             borgmatic.borg.pattern.Pattern(
-                os.path.join(borgmatic_runtime_directory, 'postgresql_databases')
+                os.path.join(borgmatic_runtime_directory, 'postgresql_databases'),
+                source=borgmatic.borg.pattern.Pattern_source.HOOK,
             )
         )
 
diff --git a/borgmatic/hooks/data_source/snapshot.py b/borgmatic/hooks/data_source/snapshot.py
index 2ee08a8f..ece63ce6 100644
--- a/borgmatic/hooks/data_source/snapshot.py
+++ b/borgmatic/hooks/data_source/snapshot.py
@@ -11,10 +11,10 @@ def get_contained_patterns(parent_directory, candidate_patterns):
     paths, but there's a parent directory (logical volume, dataset, subvolume, etc.) at /var, then
     /var is what we want to snapshot.
 
-    For this to work, a candidate pattern path can't have any globs or other non-literal characters
-    in the initial portion of the path that matches the parent directory. For instance, a parent
-    directory of /var would match a candidate pattern path of /var/log/*/data, but not a pattern
-    path like /v*/log/*/data.
+    For this function to work, a candidate pattern path can't have any globs or other non-literal
+    characters in the initial portion of the path that matches the parent directory. For instance, a
+    parent directory of /var would match a candidate pattern path of /var/log/*/data, but not a
+    pattern path like /v*/log/*/data.
 
     The one exception is that if a regular expression pattern path starts with "^", that will get
     stripped off for purposes of matching against a parent directory.
@@ -31,8 +31,10 @@ def get_contained_patterns(parent_directory, candidate_patterns):
         candidate
         for candidate in candidate_patterns
         for candidate_path in (pathlib.PurePath(candidate.path.lstrip('^')),)
-        if pathlib.PurePath(parent_directory) == candidate_path
-        or pathlib.PurePath(parent_directory) in candidate_path.parents
+        if (
+            pathlib.PurePath(parent_directory) == candidate_path
+            or pathlib.PurePath(parent_directory) in candidate_path.parents
+        )
     )
     candidate_patterns -= set(contained_patterns)
 
diff --git a/borgmatic/hooks/data_source/sqlite.py b/borgmatic/hooks/data_source/sqlite.py
index 4d5ce9a0..b36c0ccb 100644
--- a/borgmatic/hooks/data_source/sqlite.py
+++ b/borgmatic/hooks/data_source/sqlite.py
@@ -90,7 +90,8 @@ def dump_data_sources(
     if not dry_run:
         patterns.append(
             borgmatic.borg.pattern.Pattern(
-                os.path.join(borgmatic_runtime_directory, 'sqlite_databases')
+                os.path.join(borgmatic_runtime_directory, 'sqlite_databases'),
+                source=borgmatic.borg.pattern.Pattern_source.HOOK,
             )
         )
 
diff --git a/borgmatic/hooks/data_source/zfs.py b/borgmatic/hooks/data_source/zfs.py
index 82a71e7a..a7e9f01d 100644
--- a/borgmatic/hooks/data_source/zfs.py
+++ b/borgmatic/hooks/data_source/zfs.py
@@ -1,5 +1,6 @@
 import collections
 import glob
+import hashlib
 import logging
 import os
 import shutil
@@ -38,6 +39,9 @@ def get_datasets_to_backup(zfs_command, patterns):
     pattern paths represent the requested datasets to snapshot. But also include any datasets tagged
     with a borgmatic-specific user property, whether or not they appear in the patterns.
 
+    Only include datasets that contain at least one root pattern sourced from borgmatic
+    configuration (as opposed to generated elsewhere in borgmatic).
+
     Return the result as a sequence of Dataset instances, sorted by mount point.
     '''
     list_output = borgmatic.execute.execute_command_and_capture_output(
@@ -48,7 +52,7 @@ def get_datasets_to_backup(zfs_command, patterns):
             '-t',
             'filesystem',
             '-o',
-            f'name,mountpoint,{BORGMATIC_USER_PROPERTY}',
+            f'name,mountpoint,canmount,{BORGMATIC_USER_PROPERTY}',
         )
     )
 
@@ -60,7 +64,12 @@ def get_datasets_to_backup(zfs_command, patterns):
             (
                 Dataset(dataset_name, mount_point, (user_property_value == 'auto'), ())
                 for line in list_output.splitlines()
-                for (dataset_name, mount_point, user_property_value) in (line.rstrip().split('\t'),)
+                for (dataset_name, mount_point, can_mount, user_property_value) in (
+                    line.rstrip().split('\t'),
+                )
+                # Skip datasets that are marked "canmount=off", because mounting their snapshots will
+                # result in completely empty mount points—thereby preventing us from backing them up.
+                if can_mount == 'on'
             ),
             key=lambda dataset: dataset.mount_point,
             reverse=True,
@@ -83,7 +92,12 @@ def get_datasets_to_backup(zfs_command, patterns):
                 for contained_patterns in (
                     (
                         (
-                            (borgmatic.borg.pattern.Pattern(dataset.mount_point),)
+                            (
+                                borgmatic.borg.pattern.Pattern(
+                                    dataset.mount_point,
+                                    source=borgmatic.borg.pattern.Pattern_source.HOOK,
+                                ),
+                            )
                             if dataset.auto_backup
                             else ()
                         )
@@ -92,7 +106,12 @@ def get_datasets_to_backup(zfs_command, patterns):
                         )
                     ),
                 )
-                if contained_patterns
+                if dataset.auto_backup
+                or any(
+                    pattern.type == borgmatic.borg.pattern.Pattern_type.ROOT
+                    and pattern.source == borgmatic.borg.pattern.Pattern_source.CONFIG
+                    for pattern in contained_patterns
+                )
             ),
             key=lambda dataset: dataset.mount_point,
         )
@@ -155,10 +174,14 @@ def mount_snapshot(mount_command, full_snapshot_name, snapshot_mount_path):  # p
     )
 
 
-def make_borg_snapshot_pattern(pattern, normalized_runtime_directory):
+MOUNT_POINT_HASH_LENGTH = 10
+
+
+def make_borg_snapshot_pattern(pattern, dataset, normalized_runtime_directory):
     '''
-    Given a Borg pattern as a borgmatic.borg.pattern.Pattern instance, return a new Pattern with its
-    path rewritten to be in a snapshot directory based on the given runtime directory.
+    Given a Borg pattern as a borgmatic.borg.pattern.Pattern instance and the Dataset containing it,
+    return a new Pattern with its path rewritten to be in a snapshot directory based on both the
+    given runtime directory and the given Dataset's mount point.
 
     Move any initial caret in a regular expression pattern path to the beginning, so as not to break
     the regular expression.
@@ -173,6 +196,10 @@ def make_borg_snapshot_pattern(pattern, normalized_runtime_directory):
     rewritten_path = initial_caret + os.path.join(
         normalized_runtime_directory,
         'zfs_snapshots',
+        # Including this hash prevents conflicts between snapshot patterns for different datasets.
+        # For instance, without this, snapshotting a dataset at /var and another at /var/spool would
+        # result in overlapping snapshot patterns and therefore colliding mount attempts.
+        hashlib.shake_256(dataset.mount_point.encode('utf-8')).hexdigest(MOUNT_POINT_HASH_LENGTH),
         '.',  # Borg 1.4+ "slashdot" hack.
         # Included so that the source directory ends up in the Borg archive at its "original" path.
         pattern.path.lstrip('^').lstrip(os.path.sep),
@@ -183,6 +210,7 @@ def make_borg_snapshot_pattern(pattern, normalized_runtime_directory):
         pattern.type,
         pattern.style,
         pattern.device,
+        source=borgmatic.borg.pattern.Pattern_source.HOOK,
     )
 
 
@@ -209,7 +237,8 @@ def dump_data_sources(
     dry_run_label = ' (dry run; not actually snapshotting anything)' if dry_run else ''
     logger.info(f'Snapshotting ZFS datasets{dry_run_label}')
 
-    # List ZFS datasets to get their mount points.
+    # List ZFS datasets to get their mount points, but only consider those patterns that came from
+    # actual user configuration (as opposed to, say, other hooks).
     zfs_command = hook_config.get('zfs_command', 'zfs')
     requested_datasets = get_datasets_to_backup(zfs_command, patterns)
 
@@ -234,6 +263,9 @@ def dump_data_sources(
         snapshot_mount_path = os.path.join(
             normalized_runtime_directory,
             'zfs_snapshots',
+            hashlib.shake_256(dataset.mount_point.encode('utf-8')).hexdigest(
+                MOUNT_POINT_HASH_LENGTH
+            ),
             dataset.mount_point.lstrip(os.path.sep),
         )
 
@@ -249,7 +281,9 @@ def dump_data_sources(
         )
 
         for pattern in dataset.contained_patterns:
-            snapshot_pattern = make_borg_snapshot_pattern(pattern, normalized_runtime_directory)
+            snapshot_pattern = make_borg_snapshot_pattern(
+                pattern, dataset, normalized_runtime_directory
+            )
 
             # Attempt to update the pattern in place, since pattern order matters to Borg.
             try:
@@ -334,6 +368,7 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
             os.path.normpath(borgmatic_runtime_directory),
         ),
         'zfs_snapshots',
+        '*',
     )
     logger.debug(f'Looking for snapshots to remove in {snapshots_glob}{dry_run_label}')
     umount_command = hook_config.get('umount_command', 'umount')
@@ -346,7 +381,10 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
         # child datasets before the shorter mount point paths of parent datasets.
         for mount_point in reversed(dataset_mount_points):
             snapshot_mount_path = os.path.join(snapshots_directory, mount_point.lstrip(os.path.sep))
-            if not os.path.isdir(snapshot_mount_path):
+
+            # If the snapshot mount path is empty, this is probably just a "shadow" of a nested
+            # dataset and therefore there's nothing to unmount.
+            if not os.path.isdir(snapshot_mount_path) or not os.listdir(snapshot_mount_path):
                 continue
 
             # This might fail if the path is already mounted, but we swallow errors here since we'll
@@ -370,7 +408,7 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
                     return
                 except subprocess.CalledProcessError as error:
                     logger.debug(error)
-                    return
+                    continue
 
         if not dry_run:
             shutil.rmtree(snapshots_directory)
diff --git a/docs/how-to/snapshot-your-filesystems.md b/docs/how-to/snapshot-your-filesystems.md
index a9f2d267..f1b6f8e2 100644
--- a/docs/how-to/snapshot-your-filesystems.md
+++ b/docs/how-to/snapshot-your-filesystems.md
@@ -54,8 +54,8 @@ You have a couple of options for borgmatic to find and backup your ZFS datasets:
  * For any dataset you'd like backed up, add its mount point to borgmatic's
    `source_directories` option.
  * <span class="minilink minilink-addedin">New in version 1.9.6</span> Or
-   include the mount point with borgmatic's `patterns` or `patterns_from`
-   options.
+   include the mount point as a root pattern with borgmatic's `patterns` or
+   `patterns_from` options.
  * Or set the borgmatic-specific user property
    `org.torsion.borgmatic:backup=auto` onto your dataset, e.g. by running `zfs
    set org.torsion.borgmatic:backup=auto datasetname`. Then borgmatic can find
@@ -65,6 +65,11 @@ If you have multiple borgmatic configuration files with ZFS enabled, and you'd
 like particular datasets to be backed up only for particular configuration
 files, use the `source_directories` option instead of the user property.
 
+<span class="minilink minilink-addedin">New in version 1.9.11</span> borgmatic
+won't snapshot datasets with the `canmount=off` property, which is often set on
+datasets that only serve as a container for other datasets. Use `zfs get
+canmount datasetname` to see the `canmount` value for a dataset.
+
 During a backup, borgmatic automatically snapshots these discovered datasets
 (non-recursively), temporarily mounts the snapshots within its [runtime
 directory](https://torsion.org/borgmatic/docs/how-to/backup-your-databases/#runtime-directory),
@@ -147,7 +152,8 @@ For any subvolume you'd like backed up, add its path to borgmatic's
 `source_directories` option.
 
 <span class="minilink minilink-addedin">New in version 1.9.6</span> Or include
-the mount point with borgmatic's `patterns` or `patterns_from` options.
+the mount point as a root pattern with borgmatic's `patterns` or `patterns_from`
+options.
 
 During a backup, borgmatic snapshots these subvolumes (non-recursively) and
 includes the snapshotted files in the paths sent to Borg. borgmatic is also
@@ -252,7 +258,8 @@ For any logical volume you'd like backed up, add its mount point to
 borgmatic's `source_directories` option.
 
 <span class="minilink minilink-addedin">New in version 1.9.6</span> Or include
-the mount point with borgmatic's `patterns` or `patterns_from` options.
+the mount point as a root pattern with borgmatic's `patterns` or `patterns_from`
+options.
 
 During a backup, borgmatic automatically snapshots these discovered logical volumes
 (non-recursively), temporarily mounts the snapshots within its [runtime
diff --git a/tests/end-to-end/commands/fake_zfs.py b/tests/end-to-end/commands/fake_zfs.py
index 61f8ae5e..3c13f4d5 100644
--- a/tests/end-to-end/commands/fake_zfs.py
+++ b/tests/end-to-end/commands/fake_zfs.py
@@ -27,6 +27,7 @@ BUILTIN_DATASETS = (
         'used': '256K',
         'avail': '23.7M',
         'refer': '25K',
+        'canmount': 'on',
         'mountpoint': '/pool',
     },
     {
@@ -34,6 +35,7 @@ BUILTIN_DATASETS = (
         'used': '256K',
         'avail': '23.7M',
         'refer': '25K',
+        'canmount': 'on',
         'mountpoint': '/pool/dataset',
     },
 )
diff --git a/tests/unit/actions/test_create.py b/tests/unit/actions/test_create.py
index 8ba1eed0..5e4a4c9f 100644
--- a/tests/unit/actions/test_create.py
+++ b/tests/unit/actions/test_create.py
@@ -5,16 +5,21 @@ import pytest
 from flexmock import flexmock
 
 from borgmatic.actions import create as module
-from borgmatic.borg.pattern import Pattern, Pattern_style, Pattern_type
+from borgmatic.borg.pattern import Pattern, Pattern_source, Pattern_style, Pattern_type
 
 
 @pytest.mark.parametrize(
     'pattern_line,expected_pattern',
     (
-        ('R /foo', Pattern('/foo')),
-        ('P sh', Pattern('sh', Pattern_type.PATTERN_STYLE)),
-        ('+ /foo*', Pattern('/foo*', Pattern_type.INCLUDE)),
-        ('+ sh:/foo*', Pattern('/foo*', Pattern_type.INCLUDE, Pattern_style.SHELL)),
+        ('R /foo', Pattern('/foo', source=Pattern_source.CONFIG)),
+        ('P sh', Pattern('sh', Pattern_type.PATTERN_STYLE, source=Pattern_source.CONFIG)),
+        ('+ /foo*', Pattern('/foo*', Pattern_type.INCLUDE, source=Pattern_source.CONFIG)),
+        (
+            '+ sh:/foo*',
+            Pattern(
+                '/foo*', Pattern_type.INCLUDE, Pattern_style.SHELL, source=Pattern_source.CONFIG
+            ),
+        ),
     ),
 )
 def test_parse_pattern_transforms_pattern_line_to_instance(pattern_line, expected_pattern):
@@ -28,8 +33,8 @@ def test_parse_pattern_with_invalid_pattern_line_errors():
 
 def test_collect_patterns_converts_source_directories():
     assert module.collect_patterns({'source_directories': ['/foo', '/bar']}) == (
-        Pattern('/foo'),
-        Pattern('/bar'),
+        Pattern('/foo', source=Pattern_source.CONFIG),
+        Pattern('/bar', source=Pattern_source.CONFIG),
     )
 
 
@@ -48,9 +53,15 @@ def test_collect_patterns_parses_config_patterns():
 
 def test_collect_patterns_converts_exclude_patterns():
     assert module.collect_patterns({'exclude_patterns': ['/foo', '/bar', 'sh:**/baz']}) == (
-        Pattern('/foo', Pattern_type.NO_RECURSE, Pattern_style.FNMATCH),
-        Pattern('/bar', Pattern_type.NO_RECURSE, Pattern_style.FNMATCH),
-        Pattern('**/baz', Pattern_type.NO_RECURSE, Pattern_style.SHELL),
+        Pattern(
+            '/foo', Pattern_type.NO_RECURSE, Pattern_style.FNMATCH, source=Pattern_source.CONFIG
+        ),
+        Pattern(
+            '/bar', Pattern_type.NO_RECURSE, Pattern_style.FNMATCH, source=Pattern_source.CONFIG
+        ),
+        Pattern(
+            '**/baz', Pattern_type.NO_RECURSE, Pattern_style.SHELL, source=Pattern_source.CONFIG
+        ),
     )
 
 
diff --git a/tests/unit/borg/test_create.py b/tests/unit/borg/test_create.py
index 94e02425..3f1f09a7 100644
--- a/tests/unit/borg/test_create.py
+++ b/tests/unit/borg/test_create.py
@@ -4,7 +4,7 @@ import pytest
 from flexmock import flexmock
 
 from borgmatic.borg import create as module
-from borgmatic.borg.pattern import Pattern, Pattern_style, Pattern_type
+from borgmatic.borg.pattern import Pattern, Pattern_source, Pattern_style, Pattern_type
 
 from ..test_verbosity import insert_logging_mock
 
@@ -663,6 +663,7 @@ def test_make_base_create_command_with_stream_processes_ignores_read_special_fal
                 '/dev/null',
                 Pattern_type.NO_RECURSE,
                 Pattern_style.FNMATCH,
+                source=Pattern_source.INTERNAL,
             ),
         ),
         '/run/borgmatic',
@@ -713,6 +714,7 @@ def test_make_base_create_command_without_patterns_and_with_stream_processes_ign
                 '/dev/null',
                 Pattern_type.NO_RECURSE,
                 Pattern_style.FNMATCH,
+                source=Pattern_source.INTERNAL,
             ),
         ),
         '/run/borgmatic',
diff --git a/tests/unit/hooks/data_source/test_btrfs.py b/tests/unit/hooks/data_source/test_btrfs.py
index dde7b05b..648902c3 100644
--- a/tests/unit/hooks/data_source/test_btrfs.py
+++ b/tests/unit/hooks/data_source/test_btrfs.py
@@ -1,7 +1,7 @@
 import pytest
 from flexmock import flexmock
 
-from borgmatic.borg.pattern import Pattern, Pattern_style, Pattern_type
+from borgmatic.borg.pattern import Pattern, Pattern_source, Pattern_style, Pattern_type
 from borgmatic.hooks.data_source import btrfs as module
 
 
@@ -52,9 +52,14 @@ def test_get_subvolume_mount_points_with_findmnt_json_missing_filesystems_errors
 def test_get_subvolumes_collects_subvolumes_matching_patterns():
     flexmock(module).should_receive('get_subvolume_mount_points').and_return(('/mnt1', '/mnt2'))
 
+    contained_pattern = Pattern(
+        '/mnt1',
+        type=Pattern_type.ROOT,
+        source=Pattern_source.CONFIG,
+    )
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
-    ).with_args('/mnt1', object).and_return((Pattern('/mnt1'),))
+    ).with_args('/mnt1', object).and_return((contained_pattern,))
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
     ).with_args('/mnt2', object).and_return(())
@@ -66,7 +71,69 @@ def test_get_subvolumes_collects_subvolumes_matching_patterns():
             Pattern('/mnt1'),
             Pattern('/mnt3'),
         ],
-    ) == (module.Subvolume('/mnt1', contained_patterns=(Pattern('/mnt1'),)),)
+    ) == (module.Subvolume('/mnt1', contained_patterns=(contained_pattern,)),)
+
+
+def test_get_subvolumes_skips_non_root_patterns():
+    flexmock(module).should_receive('get_subvolume_mount_points').and_return(('/mnt1', '/mnt2'))
+
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/mnt1', object).and_return(
+        (
+            Pattern(
+                '/mnt1',
+                type=Pattern_type.EXCLUDE,
+                source=Pattern_source.CONFIG,
+            ),
+        )
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/mnt2', object).and_return(())
+
+    assert (
+        module.get_subvolumes(
+            'btrfs',
+            'findmnt',
+            patterns=[
+                Pattern('/mnt1'),
+                Pattern('/mnt3'),
+            ],
+        )
+        == ()
+    )
+
+
+def test_get_subvolumes_skips_non_config_patterns():
+    flexmock(module).should_receive('get_subvolume_mount_points').and_return(('/mnt1', '/mnt2'))
+
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/mnt1', object).and_return(
+        (
+            Pattern(
+                '/mnt1',
+                type=Pattern_type.ROOT,
+                source=Pattern_source.HOOK,
+            ),
+        )
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/mnt2', object).and_return(())
+
+    assert (
+        module.get_subvolumes(
+            'btrfs',
+            'findmnt',
+            patterns=[
+                Pattern('/mnt1'),
+                Pattern('/mnt3'),
+            ],
+        )
+        == ()
+    )
 
 
 def test_get_subvolumes_without_patterns_collects_all_subvolumes():
diff --git a/tests/unit/hooks/data_source/test_lvm.py b/tests/unit/hooks/data_source/test_lvm.py
index 49159905..34cf5250 100644
--- a/tests/unit/hooks/data_source/test_lvm.py
+++ b/tests/unit/hooks/data_source/test_lvm.py
@@ -1,7 +1,7 @@
 import pytest
 from flexmock import flexmock
 
-from borgmatic.borg.pattern import Pattern, Pattern_style, Pattern_type
+from borgmatic.borg.pattern import Pattern, Pattern_source, Pattern_style, Pattern_type
 from borgmatic.hooks.data_source import lvm as module
 
 
@@ -37,14 +37,20 @@ def test_get_logical_volumes_filters_by_patterns():
         }
         '''
     )
-    contained = {Pattern('/mnt/lvolume'), Pattern('/mnt/lvolume/subdir')}
+    contained = {
+        Pattern('/mnt/lvolume', source=Pattern_source.CONFIG),
+        Pattern('/mnt/lvolume/subdir', source=Pattern_source.CONFIG),
+    }
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
     ).with_args(None, contained).never()
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
     ).with_args('/mnt/lvolume', contained).and_return(
-        (Pattern('/mnt/lvolume'), Pattern('/mnt/lvolume/subdir'))
+        (
+            Pattern('/mnt/lvolume', source=Pattern_source.CONFIG),
+            Pattern('/mnt/lvolume/subdir', source=Pattern_source.CONFIG),
+        )
     )
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
@@ -54,17 +60,116 @@ def test_get_logical_volumes_filters_by_patterns():
     ).with_args('/mnt/notlvm', contained).never()
 
     assert module.get_logical_volumes(
-        'lsblk', patterns=(Pattern('/mnt/lvolume'), Pattern('/mnt/lvolume/subdir'))
+        'lsblk',
+        patterns=(
+            Pattern('/mnt/lvolume', source=Pattern_source.CONFIG),
+            Pattern('/mnt/lvolume/subdir', source=Pattern_source.CONFIG),
+        ),
     ) == (
         module.Logical_volume(
             name='vgroup-lvolume',
             device_path='/dev/mapper/vgroup-lvolume',
             mount_point='/mnt/lvolume',
-            contained_patterns=(Pattern('/mnt/lvolume'), Pattern('/mnt/lvolume/subdir')),
+            contained_patterns=(
+                Pattern('/mnt/lvolume', source=Pattern_source.CONFIG),
+                Pattern('/mnt/lvolume/subdir', source=Pattern_source.CONFIG),
+            ),
         ),
     )
 
 
+def test_get_logical_volumes_skips_non_root_patterns():
+    flexmock(module.borgmatic.execute).should_receive(
+        'execute_command_and_capture_output'
+    ).and_return(
+        '''
+        {
+            "blockdevices": [
+                {
+                   "name": "vgroup-lvolume",
+                   "path": "/dev/mapper/vgroup-lvolume",
+                   "mountpoint": "/mnt/lvolume",
+                   "type": "lvm"
+                }
+            ]
+        }
+        '''
+    )
+    contained = {
+        Pattern('/mnt/lvolume', type=Pattern_type.EXCLUDE, source=Pattern_source.CONFIG),
+        Pattern('/mnt/lvolume/subdir', type=Pattern_type.EXCLUDE, source=Pattern_source.CONFIG),
+    }
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args(None, contained).never()
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/mnt/lvolume', contained).and_return(
+        (
+            Pattern('/mnt/lvolume', type=Pattern_type.EXCLUDE, source=Pattern_source.CONFIG),
+            Pattern('/mnt/lvolume/subdir', type=Pattern_type.EXCLUDE, source=Pattern_source.CONFIG),
+        )
+    )
+
+    assert (
+        module.get_logical_volumes(
+            'lsblk',
+            patterns=(
+                Pattern('/mnt/lvolume', type=Pattern_type.EXCLUDE, source=Pattern_source.CONFIG),
+                Pattern(
+                    '/mnt/lvolume/subdir', type=Pattern_type.EXCLUDE, source=Pattern_source.CONFIG
+                ),
+            ),
+        )
+        == ()
+    )
+
+
+def test_get_logical_volumes_skips_non_config_patterns():
+    flexmock(module.borgmatic.execute).should_receive(
+        'execute_command_and_capture_output'
+    ).and_return(
+        '''
+        {
+            "blockdevices": [
+                {
+                   "name": "vgroup-lvolume",
+                   "path": "/dev/mapper/vgroup-lvolume",
+                   "mountpoint": "/mnt/lvolume",
+                   "type": "lvm"
+                }
+            ]
+        }
+        '''
+    )
+    contained = {
+        Pattern('/mnt/lvolume', source=Pattern_source.HOOK),
+        Pattern('/mnt/lvolume/subdir', source=Pattern_source.HOOK),
+    }
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args(None, contained).never()
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/mnt/lvolume', contained).and_return(
+        (
+            Pattern('/mnt/lvolume', source=Pattern_source.HOOK),
+            Pattern('/mnt/lvolume/subdir', source=Pattern_source.HOOK),
+        )
+    )
+
+    assert (
+        module.get_logical_volumes(
+            'lsblk',
+            patterns=(
+                Pattern('/mnt/lvolume', source=Pattern_source.HOOK),
+                Pattern('/mnt/lvolume/subdir', source=Pattern_source.HOOK),
+            ),
+        )
+        == ()
+    )
+
+
 def test_get_logical_volumes_with_invalid_lsblk_json_errors():
     flexmock(module.borgmatic.execute).should_receive(
         'execute_command_and_capture_output'
@@ -138,13 +243,13 @@ def test_snapshot_logical_volume_with_non_percentage_snapshot_name_uses_lvcreate
     (
         (
             Pattern('/foo/bar/baz'),
-            Pattern('/run/borgmatic/lvm_snapshots/./foo/bar/baz'),
+            Pattern('/run/borgmatic/lvm_snapshots/b33f/./foo/bar/baz'),
         ),
-        (Pattern('/foo/bar'), Pattern('/run/borgmatic/lvm_snapshots/./foo/bar')),
+        (Pattern('/foo/bar'), Pattern('/run/borgmatic/lvm_snapshots/b33f/./foo/bar')),
         (
             Pattern('^/foo/bar', Pattern_type.INCLUDE, Pattern_style.REGULAR_EXPRESSION),
             Pattern(
-                '^/run/borgmatic/lvm_snapshots/./foo/bar',
+                '^/run/borgmatic/lvm_snapshots/b33f/./foo/bar',
                 Pattern_type.INCLUDE,
                 Pattern_style.REGULAR_EXPRESSION,
             ),
@@ -152,40 +257,48 @@ def test_snapshot_logical_volume_with_non_percentage_snapshot_name_uses_lvcreate
         (
             Pattern('/foo/bar', Pattern_type.INCLUDE, Pattern_style.REGULAR_EXPRESSION),
             Pattern(
-                '/run/borgmatic/lvm_snapshots/./foo/bar',
+                '/run/borgmatic/lvm_snapshots/b33f/./foo/bar',
                 Pattern_type.INCLUDE,
                 Pattern_style.REGULAR_EXPRESSION,
             ),
         ),
-        (Pattern('/foo'), Pattern('/run/borgmatic/lvm_snapshots/./foo')),
-        (Pattern('/'), Pattern('/run/borgmatic/lvm_snapshots/./')),
+        (Pattern('/foo'), Pattern('/run/borgmatic/lvm_snapshots/b33f/./foo')),
+        (Pattern('/'), Pattern('/run/borgmatic/lvm_snapshots/b33f/./')),
     ),
 )
 def test_make_borg_snapshot_pattern_includes_slashdot_hack_and_stripped_pattern_path(
     pattern, expected_pattern
 ):
-    assert module.make_borg_snapshot_pattern(pattern, '/run/borgmatic') == expected_pattern
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
+
+    assert (
+        module.make_borg_snapshot_pattern(
+            pattern, flexmock(mount_point='/something'), '/run/borgmatic'
+        )
+        == expected_pattern
+    )
 
 
 def test_dump_data_sources_snapshots_and_mounts_and_updates_patterns():
     config = {'lvm': {}}
     patterns = [Pattern('/mnt/lvolume1/subdir'), Pattern('/mnt/lvolume2')]
-    flexmock(module).should_receive('get_logical_volumes').and_return(
-        (
-            module.Logical_volume(
-                name='lvolume1',
-                device_path='/dev/lvolume1',
-                mount_point='/mnt/lvolume1',
-                contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
-            ),
-            module.Logical_volume(
-                name='lvolume2',
-                device_path='/dev/lvolume2',
-                mount_point='/mnt/lvolume2',
-                contained_patterns=(Pattern('/mnt/lvolume2'),),
-            ),
-        )
+    logical_volumes = (
+        module.Logical_volume(
+            name='lvolume1',
+            device_path='/dev/lvolume1',
+            mount_point='/mnt/lvolume1',
+            contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
+        ),
+        module.Logical_volume(
+            name='lvolume2',
+            device_path='/dev/lvolume2',
+            mount_point='/mnt/lvolume2',
+            contained_patterns=(Pattern('/mnt/lvolume2'),),
+        ),
     )
+    flexmock(module).should_receive('get_logical_volumes').and_return(logical_volumes)
     flexmock(module.os).should_receive('getpid').and_return(1234)
     flexmock(module).should_receive('snapshot_logical_volume').with_args(
         'lvcreate', 'lvolume1_borgmatic-1234', '/dev/lvolume1', module.DEFAULT_SNAPSHOT_SIZE
@@ -203,18 +316,21 @@ def test_dump_data_sources_snapshots_and_mounts_and_updates_patterns():
     ).and_return(
         (module.Snapshot(name='lvolume2_borgmatic-1234', device_path='/dev/lvolume2_snap'),)
     )
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
     flexmock(module).should_receive('mount_snapshot').with_args(
-        'mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume1'
+        'mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
     ).once()
     flexmock(module).should_receive('mount_snapshot').with_args(
-        'mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume2'
+        'mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume1/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'))
+        Pattern('/mnt/lvolume1/subdir'), logical_volumes[0], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'))
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume2'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'))
+        Pattern('/mnt/lvolume2'), logical_volumes[1], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'))
 
     assert (
         module.dump_data_sources(
@@ -229,8 +345,8 @@ def test_dump_data_sources_snapshots_and_mounts_and_updates_patterns():
     )
 
     assert patterns == [
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'),
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'),
     ]
 
 
@@ -259,22 +375,21 @@ def test_dump_data_sources_with_no_logical_volumes_skips_snapshots():
 def test_dump_data_sources_uses_snapshot_size_for_snapshot():
     config = {'lvm': {'snapshot_size': '1000PB'}}
     patterns = [Pattern('/mnt/lvolume1/subdir'), Pattern('/mnt/lvolume2')]
-    flexmock(module).should_receive('get_logical_volumes').and_return(
-        (
-            module.Logical_volume(
-                name='lvolume1',
-                device_path='/dev/lvolume1',
-                mount_point='/mnt/lvolume1',
-                contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
-            ),
-            module.Logical_volume(
-                name='lvolume2',
-                device_path='/dev/lvolume2',
-                mount_point='/mnt/lvolume2',
-                contained_patterns=(Pattern('/mnt/lvolume2'),),
-            ),
-        )
+    logical_volumes = (
+        module.Logical_volume(
+            name='lvolume1',
+            device_path='/dev/lvolume1',
+            mount_point='/mnt/lvolume1',
+            contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
+        ),
+        module.Logical_volume(
+            name='lvolume2',
+            device_path='/dev/lvolume2',
+            mount_point='/mnt/lvolume2',
+            contained_patterns=(Pattern('/mnt/lvolume2'),),
+        ),
     )
+    flexmock(module).should_receive('get_logical_volumes').and_return(logical_volumes)
     flexmock(module.os).should_receive('getpid').and_return(1234)
     flexmock(module).should_receive('snapshot_logical_volume').with_args(
         'lvcreate',
@@ -298,18 +413,21 @@ def test_dump_data_sources_uses_snapshot_size_for_snapshot():
     ).and_return(
         (module.Snapshot(name='lvolume2_borgmatic-1234', device_path='/dev/lvolume2_snap'),)
     )
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
     flexmock(module).should_receive('mount_snapshot').with_args(
-        'mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume1'
+        'mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
     ).once()
     flexmock(module).should_receive('mount_snapshot').with_args(
-        'mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume2'
+        'mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume1/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'))
+        Pattern('/mnt/lvolume1/subdir'), logical_volumes[0], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'))
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume2'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'))
+        Pattern('/mnt/lvolume2'), logical_volumes[1], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'))
 
     assert (
         module.dump_data_sources(
@@ -324,8 +442,8 @@ def test_dump_data_sources_uses_snapshot_size_for_snapshot():
     )
 
     assert patterns == [
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'),
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'),
     ]
 
 
@@ -339,22 +457,21 @@ def test_dump_data_sources_uses_custom_commands():
         },
     }
     patterns = [Pattern('/mnt/lvolume1/subdir'), Pattern('/mnt/lvolume2')]
-    flexmock(module).should_receive('get_logical_volumes').and_return(
-        (
-            module.Logical_volume(
-                name='lvolume1',
-                device_path='/dev/lvolume1',
-                mount_point='/mnt/lvolume1',
-                contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
-            ),
-            module.Logical_volume(
-                name='lvolume2',
-                device_path='/dev/lvolume2',
-                mount_point='/mnt/lvolume2',
-                contained_patterns=(Pattern('/mnt/lvolume2'),),
-            ),
-        )
+    logical_volumes = (
+        module.Logical_volume(
+            name='lvolume1',
+            device_path='/dev/lvolume1',
+            mount_point='/mnt/lvolume1',
+            contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
+        ),
+        module.Logical_volume(
+            name='lvolume2',
+            device_path='/dev/lvolume2',
+            mount_point='/mnt/lvolume2',
+            contained_patterns=(Pattern('/mnt/lvolume2'),),
+        ),
     )
+    flexmock(module).should_receive('get_logical_volumes').and_return(logical_volumes)
     flexmock(module.os).should_receive('getpid').and_return(1234)
     flexmock(module).should_receive('snapshot_logical_volume').with_args(
         '/usr/local/bin/lvcreate',
@@ -378,18 +495,25 @@ def test_dump_data_sources_uses_custom_commands():
     ).and_return(
         (module.Snapshot(name='lvolume2_borgmatic-1234', device_path='/dev/lvolume2_snap'),)
     )
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
     flexmock(module).should_receive('mount_snapshot').with_args(
-        '/usr/local/bin/mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume1'
+        '/usr/local/bin/mount',
+        '/dev/lvolume1_snap',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).once()
     flexmock(module).should_receive('mount_snapshot').with_args(
-        '/usr/local/bin/mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume2'
+        '/usr/local/bin/mount',
+        '/dev/lvolume2_snap',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume1/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'))
+        Pattern('/mnt/lvolume1/subdir'), logical_volumes[0], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'))
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume2'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'))
+        Pattern('/mnt/lvolume2'), logical_volumes[1], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'))
 
     assert (
         module.dump_data_sources(
@@ -404,8 +528,8 @@ def test_dump_data_sources_uses_custom_commands():
     )
 
     assert patterns == [
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'),
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'),
     ]
 
 
@@ -463,22 +587,21 @@ def test_dump_data_sources_with_dry_run_skips_snapshots_and_does_not_touch_patte
 def test_dump_data_sources_ignores_mismatch_between_given_patterns_and_contained_patterns():
     config = {'lvm': {}}
     patterns = [Pattern('/hmm')]
-    flexmock(module).should_receive('get_logical_volumes').and_return(
-        (
-            module.Logical_volume(
-                name='lvolume1',
-                device_path='/dev/lvolume1',
-                mount_point='/mnt/lvolume1',
-                contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
-            ),
-            module.Logical_volume(
-                name='lvolume2',
-                device_path='/dev/lvolume2',
-                mount_point='/mnt/lvolume2',
-                contained_patterns=(Pattern('/mnt/lvolume2'),),
-            ),
-        )
+    logical_volumes = (
+        module.Logical_volume(
+            name='lvolume1',
+            device_path='/dev/lvolume1',
+            mount_point='/mnt/lvolume1',
+            contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
+        ),
+        module.Logical_volume(
+            name='lvolume2',
+            device_path='/dev/lvolume2',
+            mount_point='/mnt/lvolume2',
+            contained_patterns=(Pattern('/mnt/lvolume2'),),
+        ),
     )
+    flexmock(module).should_receive('get_logical_volumes').and_return(logical_volumes)
     flexmock(module.os).should_receive('getpid').and_return(1234)
     flexmock(module).should_receive('snapshot_logical_volume').with_args(
         'lvcreate', 'lvolume1_borgmatic-1234', '/dev/lvolume1', module.DEFAULT_SNAPSHOT_SIZE
@@ -496,18 +619,21 @@ def test_dump_data_sources_ignores_mismatch_between_given_patterns_and_contained
     ).and_return(
         (module.Snapshot(name='lvolume2_borgmatic-1234', device_path='/dev/lvolume2_snap'),)
     )
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
     flexmock(module).should_receive('mount_snapshot').with_args(
-        'mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume1'
+        'mount', '/dev/lvolume1_snap', '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
     ).once()
     flexmock(module).should_receive('mount_snapshot').with_args(
-        'mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/mnt/lvolume2'
+        'mount', '/dev/lvolume2_snap', '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume1/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'))
+        Pattern('/mnt/lvolume1/subdir'), logical_volumes[0], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'))
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/lvolume2'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'))
+        Pattern('/mnt/lvolume2'), logical_volumes[1], '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'))
 
     assert (
         module.dump_data_sources(
@@ -523,8 +649,8 @@ def test_dump_data_sources_ignores_mismatch_between_given_patterns_and_contained
 
     assert patterns == [
         Pattern('/hmm'),
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume1/subdir'),
-        Pattern('/run/borgmatic/lvm_snapshots/./mnt/lvolume2'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume1/subdir'),
+        Pattern('/run/borgmatic/lvm_snapshots/b33f/./mnt/lvolume2'),
     ]
 
 
@@ -694,16 +820,19 @@ def test_remove_data_source_dumps_unmounts_and_remove_snapshots():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).once()
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).once()
     flexmock(module).should_receive('get_snapshots').and_return(
         (
@@ -799,9 +928,11 @@ def test_remove_data_source_dumps_with_missing_snapshot_directory_skips_unmount(
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots'
+        '/run/borgmatic/lvm_snapshots/b33f'
     ).and_return(False)
     flexmock(module.shutil).should_receive('rmtree').never()
     flexmock(module).should_receive('unmount_snapshot').never()
@@ -843,24 +974,92 @@ def test_remove_data_source_dumps_with_missing_snapshot_mount_path_skips_unmount
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots'
+        '/run/borgmatic/lvm_snapshots/b33f'
     ).and_return(True)
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1'
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
     ).and_return(False)
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2'
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
     ).and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).never()
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
+    ).once()
+    flexmock(module).should_receive('get_snapshots').and_return(
+        (
+            module.Snapshot('lvolume1_borgmatic-1234', '/dev/lvolume1'),
+            module.Snapshot('lvolume2_borgmatic-1234', '/dev/lvolume2'),
+        ),
+    )
+    flexmock(module).should_receive('remove_snapshot').with_args('lvremove', '/dev/lvolume1').once()
+    flexmock(module).should_receive('remove_snapshot').with_args('lvremove', '/dev/lvolume2').once()
+
+    module.remove_data_source_dumps(
+        hook_config=config['lvm'],
+        config=config,
+        borgmatic_runtime_directory='/run/borgmatic',
+        dry_run=False,
+    )
+
+
+def test_remove_data_source_dumps_with_empty_snapshot_mount_path_skips_unmount():
+    config = {'lvm': {}}
+    flexmock(module).should_receive('get_logical_volumes').and_return(
+        (
+            module.Logical_volume(
+                name='lvolume1',
+                device_path='/dev/lvolume1',
+                mount_point='/mnt/lvolume1',
+                contained_patterns=(Pattern('/mnt/lvolume1/subdir'),),
+            ),
+            module.Logical_volume(
+                name='lvolume2',
+                device_path='/dev/lvolume2',
+                mount_point='/mnt/lvolume2',
+                contained_patterns=(Pattern('/mnt/lvolume2'),),
+            ),
+        )
+    )
+    flexmock(module.borgmatic.config.paths).should_receive(
+        'replace_temporary_subdirectory_with_glob'
+    ).and_return('/run/borgmatic')
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
+    flexmock(module.os.path).should_receive('isdir').with_args(
+        '/run/borgmatic/lvm_snapshots/b33f'
+    ).and_return(True)
+    flexmock(module.os.path).should_receive('isdir').with_args(
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
+    ).and_return(True)
+    flexmock(module.os).should_receive('listdir').with_args(
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
+    ).and_return([])
+    flexmock(module.os.path).should_receive('isdir').with_args(
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
+    ).and_return(True)
+    flexmock(module.os).should_receive('listdir').with_args(
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
+    ).and_return(['file.txt'])
+    flexmock(module.shutil).should_receive('rmtree')
+    flexmock(module).should_receive('unmount_snapshot').with_args(
+        'umount',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
+    ).never()
+    flexmock(module).should_receive('unmount_snapshot').with_args(
+        'umount',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).once()
     flexmock(module).should_receive('get_snapshots').and_return(
         (
@@ -900,24 +1099,27 @@ def test_remove_data_source_dumps_with_successful_mount_point_removal_skips_unmo
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots'
+        '/run/borgmatic/lvm_snapshots/b33f'
     ).and_return(True)
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1'
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1'
     ).and_return(True).and_return(False)
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2'
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2'
     ).and_return(True).and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).never()
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).once()
     flexmock(module).should_receive('get_snapshots').and_return(
         (
@@ -957,16 +1159,19 @@ def test_remove_data_source_dumps_bails_for_missing_umount_command():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).and_raise(FileNotFoundError)
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).never()
     flexmock(module).should_receive('get_snapshots').never()
     flexmock(module).should_receive('remove_snapshot').never()
@@ -979,7 +1184,7 @@ def test_remove_data_source_dumps_bails_for_missing_umount_command():
     )
 
 
-def test_remove_data_source_dumps_bails_for_umount_command_error():
+def test_remove_data_source_dumps_swallows_umount_command_error():
     config = {'lvm': {}}
     flexmock(module).should_receive('get_logical_volumes').and_return(
         (
@@ -1000,19 +1205,28 @@ def test_remove_data_source_dumps_bails_for_umount_command_error():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).and_raise(module.subprocess.CalledProcessError(1, 'wtf'))
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
-    ).never()
-    flexmock(module).should_receive('get_snapshots').never()
-    flexmock(module).should_receive('remove_snapshot').never()
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
+    ).once()
+    flexmock(module).should_receive('get_snapshots').and_return(
+        (
+            module.Snapshot('lvolume1_borgmatic-1234', '/dev/lvolume1'),
+            module.Snapshot('lvolume2_borgmatic-1234', '/dev/lvolume2'),
+        ),
+    )
+    flexmock(module).should_receive('remove_snapshot').with_args('lvremove', '/dev/lvolume1').once()
+    flexmock(module).should_receive('remove_snapshot').with_args('lvremove', '/dev/lvolume2').once()
 
     module.remove_data_source_dumps(
         hook_config=config['lvm'],
@@ -1043,16 +1257,19 @@ def test_remove_data_source_dumps_bails_for_missing_lvs_command():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).once()
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).once()
     flexmock(module).should_receive('get_snapshots').and_raise(FileNotFoundError)
     flexmock(module).should_receive('remove_snapshot').never()
@@ -1086,16 +1303,19 @@ def test_remove_data_source_dumps_bails_for_lvs_command_error():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume1',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume1',
     ).once()
     flexmock(module).should_receive('unmount_snapshot').with_args(
         'umount',
-        '/run/borgmatic/lvm_snapshots/mnt/lvolume2',
+        '/run/borgmatic/lvm_snapshots/b33f/mnt/lvolume2',
     ).once()
     flexmock(module).should_receive('get_snapshots').and_raise(
         module.subprocess.CalledProcessError(1, 'wtf')
@@ -1133,6 +1353,7 @@ def test_remove_data_source_with_dry_run_skips_snapshot_unmount_and_delete():
     ).and_return('/run/borgmatic')
     flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree').never()
     flexmock(module).should_receive('unmount_snapshot').never()
     flexmock(module).should_receive('get_snapshots').and_return(
diff --git a/tests/unit/hooks/data_source/test_zfs.py b/tests/unit/hooks/data_source/test_zfs.py
index 85782bdb..fbe18fa9 100644
--- a/tests/unit/hooks/data_source/test_zfs.py
+++ b/tests/unit/hooks/data_source/test_zfs.py
@@ -3,7 +3,7 @@ import os
 import pytest
 from flexmock import flexmock
 
-from borgmatic.borg.pattern import Pattern, Pattern_style, Pattern_type
+from borgmatic.borg.pattern import Pattern, Pattern_source, Pattern_style, Pattern_type
 from borgmatic.hooks.data_source import zfs as module
 
 
@@ -11,11 +11,19 @@ def test_get_datasets_to_backup_filters_datasets_by_patterns():
     flexmock(module.borgmatic.execute).should_receive(
         'execute_command_and_capture_output'
     ).and_return(
-        'dataset\t/dataset\t-\nother\t/other\t-',
+        'dataset\t/dataset\ton\t-\nother\t/other\ton\t-',
     )
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
-    ).with_args('/dataset', object).and_return((Pattern('/dataset'),))
+    ).with_args('/dataset', object).and_return(
+        (
+            Pattern(
+                '/dataset',
+                Pattern_type.ROOT,
+                source=Pattern_source.CONFIG,
+            ),
+        )
+    )
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
     ).with_args('/other', object).and_return(())
@@ -23,24 +31,134 @@ def test_get_datasets_to_backup_filters_datasets_by_patterns():
     assert module.get_datasets_to_backup(
         'zfs',
         patterns=(
-            Pattern('/foo'),
-            Pattern('/dataset'),
-            Pattern('/bar'),
+            Pattern(
+                '/foo',
+                Pattern_type.ROOT,
+                source=Pattern_source.CONFIG,
+            ),
+            Pattern(
+                '/dataset',
+                Pattern_type.ROOT,
+                source=Pattern_source.CONFIG,
+            ),
+            Pattern(
+                '/bar',
+                Pattern_type.ROOT,
+                source=Pattern_source.CONFIG,
+            ),
         ),
     ) == (
         module.Dataset(
             name='dataset',
             mount_point='/dataset',
-            contained_patterns=(Pattern('/dataset'),),
+            contained_patterns=(
+                Pattern(
+                    '/dataset',
+                    Pattern_type.ROOT,
+                    source=Pattern_source.CONFIG,
+                ),
+            ),
         ),
     )
 
 
+def test_get_datasets_to_backup_skips_non_root_patterns():
+    flexmock(module.borgmatic.execute).should_receive(
+        'execute_command_and_capture_output'
+    ).and_return(
+        'dataset\t/dataset\ton\t-\nother\t/other\ton\t-',
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/dataset', object).and_return(
+        (
+            Pattern(
+                '/dataset',
+                Pattern_type.EXCLUDE,
+                source=Pattern_source.CONFIG,
+            ),
+        )
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/other', object).and_return(())
+
+    assert (
+        module.get_datasets_to_backup(
+            'zfs',
+            patterns=(
+                Pattern(
+                    '/foo',
+                    Pattern_type.ROOT,
+                    source=Pattern_source.CONFIG,
+                ),
+                Pattern(
+                    '/dataset',
+                    Pattern_type.EXCLUDE,
+                    source=Pattern_source.CONFIG,
+                ),
+                Pattern(
+                    '/bar',
+                    Pattern_type.ROOT,
+                    source=Pattern_source.CONFIG,
+                ),
+            ),
+        )
+        == ()
+    )
+
+
+def test_get_datasets_to_backup_skips_non_config_patterns():
+    flexmock(module.borgmatic.execute).should_receive(
+        'execute_command_and_capture_output'
+    ).and_return(
+        'dataset\t/dataset\ton\t-\nother\t/other\ton\t-',
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/dataset', object).and_return(
+        (
+            Pattern(
+                '/dataset',
+                Pattern_type.ROOT,
+                source=Pattern_source.HOOK,
+            ),
+        )
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/other', object).and_return(())
+
+    assert (
+        module.get_datasets_to_backup(
+            'zfs',
+            patterns=(
+                Pattern(
+                    '/foo',
+                    Pattern_type.ROOT,
+                    source=Pattern_source.CONFIG,
+                ),
+                Pattern(
+                    '/dataset',
+                    Pattern_type.ROOT,
+                    source=Pattern_source.HOOK,
+                ),
+                Pattern(
+                    '/bar',
+                    Pattern_type.ROOT,
+                    source=Pattern_source.CONFIG,
+                ),
+            ),
+        )
+        == ()
+    )
+
+
 def test_get_datasets_to_backup_filters_datasets_by_user_property():
     flexmock(module.borgmatic.execute).should_receive(
         'execute_command_and_capture_output'
     ).and_return(
-        'dataset\t/dataset\tauto\nother\t/other\t-',
+        'dataset\t/dataset\ton\tauto\nother\t/other\ton\t-',
     )
     flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
         'get_contained_patterns'
@@ -49,16 +167,45 @@ def test_get_datasets_to_backup_filters_datasets_by_user_property():
         'get_contained_patterns'
     ).with_args('/other', object).and_return(())
 
-    assert module.get_datasets_to_backup('zfs', patterns=(Pattern('/foo'), Pattern('/bar'))) == (
+    assert module.get_datasets_to_backup(
+        'zfs',
+        patterns=(Pattern('/foo'), Pattern('/bar')),
+    ) == (
         module.Dataset(
             name='dataset',
             mount_point='/dataset',
             auto_backup=True,
-            contained_patterns=(Pattern('/dataset'),),
+            contained_patterns=(Pattern('/dataset', source=Pattern_source.HOOK),),
         ),
     )
 
 
+def test_get_datasets_to_backup_filters_datasets_by_canmount_property():
+    flexmock(module.borgmatic.execute).should_receive(
+        'execute_command_and_capture_output'
+    ).and_return(
+        'dataset\t/dataset\toff\t-\nother\t/other\ton\t-',
+    )
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/dataset', object).and_return((Pattern('/dataset'),))
+    flexmock(module.borgmatic.hooks.data_source.snapshot).should_receive(
+        'get_contained_patterns'
+    ).with_args('/other', object).and_return(())
+
+    assert (
+        module.get_datasets_to_backup(
+            'zfs',
+            patterns=(
+                Pattern('/foo'),
+                Pattern('/dataset'),
+                Pattern('/bar'),
+            ),
+        )
+        == ()
+    )
+
+
 def test_get_datasets_to_backup_with_invalid_list_output_raises():
     flexmock(module.borgmatic.execute).should_receive(
         'execute_command_and_capture_output'
@@ -94,13 +241,13 @@ def test_get_all_dataset_mount_points_does_not_filter_datasets():
     (
         (
             Pattern('/foo/bar/baz'),
-            Pattern('/run/borgmatic/zfs_snapshots/./foo/bar/baz'),
+            Pattern('/run/borgmatic/zfs_snapshots/b33f/./foo/bar/baz'),
         ),
-        (Pattern('/foo/bar'), Pattern('/run/borgmatic/zfs_snapshots/./foo/bar')),
+        (Pattern('/foo/bar'), Pattern('/run/borgmatic/zfs_snapshots/b33f/./foo/bar')),
         (
             Pattern('^/foo/bar', Pattern_type.INCLUDE, Pattern_style.REGULAR_EXPRESSION),
             Pattern(
-                '^/run/borgmatic/zfs_snapshots/./foo/bar',
+                '^/run/borgmatic/zfs_snapshots/b33f/./foo/bar',
                 Pattern_type.INCLUDE,
                 Pattern_style.REGULAR_EXPRESSION,
             ),
@@ -108,46 +255,55 @@ def test_get_all_dataset_mount_points_does_not_filter_datasets():
         (
             Pattern('/foo/bar', Pattern_type.INCLUDE, Pattern_style.REGULAR_EXPRESSION),
             Pattern(
-                '/run/borgmatic/zfs_snapshots/./foo/bar',
+                '/run/borgmatic/zfs_snapshots/b33f/./foo/bar',
                 Pattern_type.INCLUDE,
                 Pattern_style.REGULAR_EXPRESSION,
             ),
         ),
-        (Pattern('/foo'), Pattern('/run/borgmatic/zfs_snapshots/./foo')),
-        (Pattern('/'), Pattern('/run/borgmatic/zfs_snapshots/./')),
+        (Pattern('/foo'), Pattern('/run/borgmatic/zfs_snapshots/b33f/./foo')),
+        (Pattern('/'), Pattern('/run/borgmatic/zfs_snapshots/b33f/./')),
     ),
 )
 def test_make_borg_snapshot_pattern_includes_slashdot_hack_and_stripped_pattern_path(
     pattern, expected_pattern
 ):
-    assert module.make_borg_snapshot_pattern(pattern, '/run/borgmatic') == expected_pattern
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
+
+    assert (
+        module.make_borg_snapshot_pattern(
+            pattern, flexmock(mount_point='/something'), '/run/borgmatic'
+        )
+        == expected_pattern
+    )
 
 
 def test_dump_data_sources_snapshots_and_mounts_and_updates_patterns():
-    flexmock(module).should_receive('get_datasets_to_backup').and_return(
-        (
-            flexmock(
-                name='dataset',
-                mount_point='/mnt/dataset',
-                contained_patterns=(Pattern('/mnt/dataset/subdir'),),
-            )
-        )
+    dataset = flexmock(
+        name='dataset',
+        mount_point='/mnt/dataset',
+        contained_patterns=(Pattern('/mnt/dataset/subdir'),),
     )
+    flexmock(module).should_receive('get_datasets_to_backup').and_return((dataset,))
     flexmock(module.os).should_receive('getpid').and_return(1234)
     full_snapshot_name = 'dataset@borgmatic-1234'
     flexmock(module).should_receive('snapshot_dataset').with_args(
         'zfs',
         full_snapshot_name,
     ).once()
-    snapshot_mount_path = '/run/borgmatic/zfs_snapshots/./mnt/dataset'
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
+    snapshot_mount_path = '/run/borgmatic/zfs_snapshots/b33f/./mnt/dataset'
     flexmock(module).should_receive('mount_snapshot').with_args(
         'mount',
         full_snapshot_name,
         module.os.path.normpath(snapshot_mount_path),
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/dataset/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/zfs_snapshots/./mnt/dataset/subdir'))
+        Pattern('/mnt/dataset/subdir'), dataset, '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/zfs_snapshots/b33f/./mnt/dataset/subdir'))
     patterns = [Pattern('/mnt/dataset/subdir')]
 
     assert (
@@ -188,30 +344,30 @@ def test_dump_data_sources_with_no_datasets_skips_snapshots():
 
 
 def test_dump_data_sources_uses_custom_commands():
-    flexmock(module).should_receive('get_datasets_to_backup').and_return(
-        (
-            flexmock(
-                name='dataset',
-                mount_point='/mnt/dataset',
-                contained_patterns=(Pattern('/mnt/dataset/subdir'),),
-            )
-        )
+    dataset = flexmock(
+        name='dataset',
+        mount_point='/mnt/dataset',
+        contained_patterns=(Pattern('/mnt/dataset/subdir'),),
     )
+    flexmock(module).should_receive('get_datasets_to_backup').and_return((dataset,))
     flexmock(module.os).should_receive('getpid').and_return(1234)
     full_snapshot_name = 'dataset@borgmatic-1234'
     flexmock(module).should_receive('snapshot_dataset').with_args(
         '/usr/local/bin/zfs',
         full_snapshot_name,
     ).once()
-    snapshot_mount_path = '/run/borgmatic/zfs_snapshots/./mnt/dataset'
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
+    snapshot_mount_path = '/run/borgmatic/zfs_snapshots/b33f/./mnt/dataset'
     flexmock(module).should_receive('mount_snapshot').with_args(
         '/usr/local/bin/mount',
         full_snapshot_name,
         module.os.path.normpath(snapshot_mount_path),
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/dataset/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/zfs_snapshots/./mnt/dataset/subdir'))
+        Pattern('/mnt/dataset/subdir'), dataset, '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/zfs_snapshots/b33f/./mnt/dataset/subdir'))
     patterns = [Pattern('/mnt/dataset/subdir')]
     hook_config = {
         'zfs_command': '/usr/local/bin/zfs',
@@ -261,30 +417,30 @@ def test_dump_data_sources_with_dry_run_skips_commands_and_does_not_touch_patter
 
 
 def test_dump_data_sources_ignores_mismatch_between_given_patterns_and_contained_patterns():
-    flexmock(module).should_receive('get_datasets_to_backup').and_return(
-        (
-            flexmock(
-                name='dataset',
-                mount_point='/mnt/dataset',
-                contained_patterns=(Pattern('/mnt/dataset/subdir'),),
-            )
-        )
+    dataset = flexmock(
+        name='dataset',
+        mount_point='/mnt/dataset',
+        contained_patterns=(Pattern('/mnt/dataset/subdir'),),
     )
+    flexmock(module).should_receive('get_datasets_to_backup').and_return((dataset,))
     flexmock(module.os).should_receive('getpid').and_return(1234)
     full_snapshot_name = 'dataset@borgmatic-1234'
     flexmock(module).should_receive('snapshot_dataset').with_args(
         'zfs',
         full_snapshot_name,
     ).once()
-    snapshot_mount_path = '/run/borgmatic/zfs_snapshots/./mnt/dataset'
+    flexmock(module.hashlib).should_receive('shake_256').and_return(
+        flexmock(hexdigest=lambda length: 'b33f')
+    )
+    snapshot_mount_path = '/run/borgmatic/zfs_snapshots/b33f/./mnt/dataset'
     flexmock(module).should_receive('mount_snapshot').with_args(
         'mount',
         full_snapshot_name,
         module.os.path.normpath(snapshot_mount_path),
     ).once()
     flexmock(module).should_receive('make_borg_snapshot_pattern').with_args(
-        Pattern('/mnt/dataset/subdir'), '/run/borgmatic'
-    ).and_return(Pattern('/run/borgmatic/zfs_snapshots/./mnt/dataset/subdir'))
+        Pattern('/mnt/dataset/subdir'), dataset, '/run/borgmatic'
+    ).and_return(Pattern('/run/borgmatic/zfs_snapshots/b33f/./mnt/dataset/subdir'))
     patterns = [Pattern('/hmm')]
 
     assert (
@@ -317,11 +473,14 @@ def test_remove_data_source_dumps_unmounts_and_destroys_snapshots():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
-        'umount', '/run/borgmatic/zfs_snapshots/mnt/dataset'
+        'umount', '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
     ).once()
     flexmock(module).should_receive('get_all_snapshots').and_return(
         ('dataset@borgmatic-1234', 'dataset@other', 'other@other', 'invalid')
@@ -343,11 +502,14 @@ def test_remove_data_source_dumps_use_custom_commands():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
-        '/usr/local/bin/umount', '/run/borgmatic/zfs_snapshots/mnt/dataset'
+        '/usr/local/bin/umount', '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
     ).once()
     flexmock(module).should_receive('get_all_snapshots').and_return(
         ('dataset@borgmatic-1234', 'dataset@other', 'other@other', 'invalid')
@@ -416,11 +578,14 @@ def test_remove_data_source_dumps_bails_for_missing_umount_command():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
-        '/usr/local/bin/umount', '/run/borgmatic/zfs_snapshots/mnt/dataset'
+        '/usr/local/bin/umount', '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
     ).and_raise(FileNotFoundError)
     flexmock(module).should_receive('get_all_snapshots').never()
     flexmock(module).should_receive('destroy_snapshot').never()
@@ -434,19 +599,26 @@ def test_remove_data_source_dumps_bails_for_missing_umount_command():
     )
 
 
-def test_remove_data_source_dumps_bails_for_umount_command_error():
+def test_remove_data_source_dumps_swallows_umount_command_error():
     flexmock(module).should_receive('get_all_dataset_mount_points').and_return(('/mnt/dataset',))
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').with_args(
-        '/usr/local/bin/umount', '/run/borgmatic/zfs_snapshots/mnt/dataset'
+        '/usr/local/bin/umount', '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
     ).and_raise(module.subprocess.CalledProcessError(1, 'wtf'))
-    flexmock(module).should_receive('get_all_snapshots').never()
-    flexmock(module).should_receive('destroy_snapshot').never()
+    flexmock(module).should_receive('get_all_snapshots').and_return(
+        ('dataset@borgmatic-1234', 'dataset@other', 'other@other', 'invalid')
+    )
+    flexmock(module).should_receive('destroy_snapshot').with_args(
+        '/usr/local/bin/zfs', 'dataset@borgmatic-1234'
+    ).once()
     hook_config = {'zfs_command': '/usr/local/bin/zfs', 'umount_command': '/usr/local/bin/umount'}
 
     module.remove_data_source_dumps(
@@ -462,7 +634,9 @@ def test_remove_data_source_dumps_skips_unmount_snapshot_directories_that_are_no
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(False)
     flexmock(module.shutil).should_receive('rmtree').never()
     flexmock(module).should_receive('unmount_snapshot').never()
@@ -486,13 +660,50 @@ def test_remove_data_source_dumps_skips_unmount_snapshot_mount_paths_that_are_no
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/zfs_snapshots'
+        '/run/borgmatic/zfs_snapshots/b33f'
     ).and_return(True)
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/zfs_snapshots/mnt/dataset'
+        '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
     ).and_return(False)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
+    flexmock(module.shutil).should_receive('rmtree')
+    flexmock(module).should_receive('unmount_snapshot').never()
+    flexmock(module).should_receive('get_all_snapshots').and_return(
+        ('dataset@borgmatic-1234', 'dataset@other', 'other@other', 'invalid')
+    )
+    flexmock(module).should_receive('destroy_snapshot').with_args(
+        'zfs', 'dataset@borgmatic-1234'
+    ).once()
+
+    module.remove_data_source_dumps(
+        hook_config={},
+        config={'source_directories': '/mnt/dataset', 'zfs': {}},
+        borgmatic_runtime_directory='/run/borgmatic',
+        dry_run=False,
+    )
+
+
+def test_remove_data_source_dumps_skips_unmount_snapshot_mount_paths_that_are_empty():
+    flexmock(module).should_receive('get_all_dataset_mount_points').and_return(('/mnt/dataset',))
+    flexmock(module.borgmatic.config.paths).should_receive(
+        'replace_temporary_subdirectory_with_glob'
+    ).and_return('/run/borgmatic')
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
+    flexmock(module.os.path).should_receive('isdir').with_args(
+        '/run/borgmatic/zfs_snapshots/b33f'
+    ).and_return(True)
+    flexmock(module.os.path).should_receive('isdir').with_args(
+        '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
+    ).and_return(True)
+    flexmock(module.os).should_receive('listdir').with_args(
+        '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
+    ).and_return([])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').never()
     flexmock(module).should_receive('get_all_snapshots').and_return(
@@ -515,13 +726,16 @@ def test_remove_data_source_dumps_skips_unmount_snapshot_mount_paths_after_rmtre
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/zfs_snapshots'
+        '/run/borgmatic/zfs_snapshots/b33f'
     ).and_return(True)
     flexmock(module.os.path).should_receive('isdir').with_args(
-        '/run/borgmatic/zfs_snapshots/mnt/dataset'
+        '/run/borgmatic/zfs_snapshots/b33f/mnt/dataset'
     ).and_return(True).and_return(False)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree')
     flexmock(module).should_receive('unmount_snapshot').never()
     flexmock(module).should_receive('get_all_snapshots').and_return(
@@ -544,8 +758,11 @@ def test_remove_data_source_dumps_with_dry_run_skips_unmount_and_destroy():
     flexmock(module.borgmatic.config.paths).should_receive(
         'replace_temporary_subdirectory_with_glob'
     ).and_return('/run/borgmatic')
-    flexmock(module.glob).should_receive('glob').replace_with(lambda path: [path])
+    flexmock(module.glob).should_receive('glob').replace_with(
+        lambda path: [path.replace('*', 'b33f')]
+    )
     flexmock(module.os.path).should_receive('isdir').and_return(True)
+    flexmock(module.os).should_receive('listdir').and_return(['file.txt'])
     flexmock(module.shutil).should_receive('rmtree').never()
     flexmock(module).should_receive('unmount_snapshot').never()
     flexmock(module).should_receive('get_all_snapshots').and_return(