systemctl enable --now autosnap.timer
autosnap creates snapshots of ZFS datasets regularly and purges old snapshots based on a
keep-x-in-timeframe retention policy. It is a simpler replacement for zfs-auto-snapshot.
See zfs(8) for details on creating and destroying ZFS snapshots manually.
When autosnap is installed you can use it on the commandline or enable the included systemd
timer for fully automatic operation. The systemd unit by default runs on all datasets and must
be configured through ZFS properties. Retention policies cannot be given on the commandline and
must be configured with properties in any case.
autosnap [-l] [-v] [dataset [...]]
-
dataset: give the datasets to operate on recursively as arguments, no arguments means "all available"
-
-l: only show an overview of datasets and their explicitly configured retention policies, then exit
-
-v: be verbose and print what we're doing (created/destroyed datasets)
Configure autosnap by setting properties on the ZFS datasets directly with
zfs set ansemjo:autosnap:... pool/dataset. Available properties are:
| property | valid values | meaning |
|---|---|---|
| ansemjo:autosnap | boolean | perform autosnapshots and purging on this dataset at all |
| ansemjo:autosnap:keep_minimum | positive integer | keep at least x snapshots, regardless of age |
| ansemjo:autosnap:keep_minutes | positive integer | keep at least x minutes of snapshots |
| ansemjo:autosnap:keep_hours | positive integer | keep at least x hours of snapshots |
| ansemjo:autosnap:keep_days | positive integer | keep at least x days of snapshots |
| ansemjo:autosnap:keep_weeks | positive integer | keep at least x weeks of snapshots |
| ansemjo:autosnap:keep_months | positive integer | keep at least x months of snapshots |
| ansemjo:autosnap:keep_years | positive integer | keep at least x years of snapshots |
If ansemjo:autosnap is not set to a truthy value, autosnap will not operate on this dataset. Truthy can
be y, yes, true, on or 1. Anything alse will be false.
ZFS properties are inherited by default, so if you want to enable snapshotting for an entire subtree of datasets
simply set ansemjo:autosnap=yes on its root. To reset a property to its inherited value use
zfs inherit ansemjo:autosnap:... pool/dataset.
For example setting ansemjo:autosnap:keep_days to 7 means that for every day one snapshot will be kept,
up to a maximum of 7 days. This does not mean that the oldest snapshot can be 8 days old, however. If you
only have snapshots every second day, you oldest snapshot according to this policy will be 14 days old.
See ansemjo/datesieve for details.
By default, if no explicit policies are configured, autosnap will keep:
- at least 3
- 4 minutes
- 24 hours
- 7 days
- 4 weeks
- 12 months
- 10 years
Install one of the rpm or deb packages from the Releases page.
Alternatively clone the repository or download and extract a release and use make install to
install the script and unit files manually.
For automatic purging datesieve is required. You can
install it quickly with pip:
pip install git+https://github.com/ansemjo/datesieve