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Helper script to remove old ZFS snapshots
#!/usr/bin/env python3
Helper script to remove old ZFS snapshots
Copyright (c) Onlime GmbH,
import argparse
from re import compile
from datetime import datetime, timedelta
from subprocess import check_output
import sys
def list_snapshots(age: int, prefix: str = None, exclude: str = None, dataset: str = None, destroy: bool = False):
# List all snapshot names of a dataset sorted by creation date; sample command:
# $ zfs list -H -t snapshot -o name,creation -s creation [<dataset>]
cmd = ['zfs', 'list', '-H', '-t', 'snapshot', '-o', 'name,creation', '-s', 'creation']
if dataset:
snap_list = check_output(cmd).decode(sys.stdout.encoding)
snap_lines = snap_list.splitlines()
# reverse sort order (`zfs list` only supports asc sort order), newest snapshots on top
for line in snap_lines:
snapshot, creation = line.split('\t')
if prefix and '@{}'.format(prefix) not in snapshot:
if exclude and exclude in snapshot:
snap_date = datetime.strptime(creation, '%a %b %d %H:%M %Y')
if snap_date <
print('{}{} {}'.format(
'DESTROYING ' if destroy else '',
snap_date.strftime('%Y-%m-%d %H:%M'),
if destroy:
check_output(['zfs', 'destroy', snapshot])
if __name__ == "__main__": # Only use the argument parsing if the script was called as script and not imported
# argument parsing
parser = argparse.ArgumentParser()
parser.add_argument("age", type=int, help="List snapshots that are older than age (hours).")
parser.add_argument("--prefix", help="Only list snapshot with this prefix.")
parser.add_argument("--exclude", help="Exclude snapshots that contain this string.")
parser.add_argument("--dataset", help="Limit to a specific dataset.")
parser.add_argument("--destroy", action='store_true', help="Destroy snapshots that are older than age.")
args = parser.parse_args()
list_snapshots(args.age, args.prefix, args.exclude, args.dataset, args.destroy)
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