Pruning Snapshots

plakar prune removes snapshots from a Kloset store. Snapshots can be selected for removal by age, tag, or retention policy.

By default, plakar prune runs in dry-run mode and makes no changes, you’ll need to pass -apply to execute the operation.

On this guide, we will use a Kloset store is located at $HOME/backups, but your store can be located anywhere else:

Before removing anything, check which snapshots would be affected:

$ plakar at $HOME/backups prune -days 30

No snapshots are deleted without -apply. The output shows what would be removed.

To delete snapshots older than 30 days:

$ plakar at $HOME/backups prune -days 30 -apply

You can use other flags like -weeks, -months, or -years to specify age.

To delete snapshots older than 30 days that carry a specific tag:

$ plakar at $HOME/backups prune -days 30 -tag daily-backup -apply

Only snapshots matching the tag are considered. Others are left untouched.

A retention policy keeps a defined number of snapshots across different time windows and deletes everything else. This is the most common way to keep a store bounded over time.

$ plakar at $HOME/backups prune \
  -days 1 -per-day 7 \
  -weeks 4 -per-week 1 \
  -months 12 -per-month 1 \
  -years 5 -per-year 1 \
  -apply

This can be broken down as:

• -days 1 -per-day 7 — For the past day, keep up to 7 snapshots. This preserves frequent checkpoints in the most recent period.
• -weeks 4 -per-week 1 — For the past 4 weeks, keep 1 snapshot per week. Older intra-day snapshots are pruned down to a single representative per week.
• -months 12 -per-month 1 — For the past 12 months, keep 1 snapshot per month.
• -years 5 -per-year 1 — For the past 5 years, keep 1 snapshot per year.

Everything outside those windows is deleted.

Rather than specifying retention parameters on the command line each time, a named policy can be defined once and reused.

You can create a policy and configure its retention parameters:

$ plakar policy add weekly
$ plakar policy set weekly since='3 months'
$ plakar policy set weekly per-week=1

Then apply the policy:

$ plakar at $HOME/backups prune -policy weekly -apply

$ plakar policy show              # list all policies (YAML by default)
$ plakar policy show -json        # output as JSON
$ plakar policy show weekly       # inspect a specific policy
$ plakar policy set weekly per-week=2   # update a parameter
$ plakar policy unset weekly per-week   # remove a parameter
$ plakar policy rm weekly         # delete a policy

Pruning removes snapshots, but does not immediately free storage. Because Plakar deduplicates data across snapshots, the underlying chunks and packfiles remain until plakar maintenance runs (also consider the maintenance grace period).

After pruning, run plakar maintenance to reclaim the freed space:

$ plakar maintenance

• plakar policy
• How maintenance works