Ubuntu Manpage: borg-prune - Prune repository archives according to specified rules

NAME

       borg-prune - Prune repository archives according to specified rules

SYNOPSIS

       borg [common options] prune [options] [REPOSITORY]

DESCRIPTION

The prune command prunes a repository by deleting all archives not matching any of the
specified retention options.

Important: Repository disk space is not freed until you run borg compact.

This command is normally used by automated backup scripts wanting to keep a certain number
of historic backups. This retention policy is commonly referred to as GFS
(Grandfather-father-son) backup rotation scheme.

Also, prune automatically removes checkpoint archives (incomplete archives left behind by
interrupted backup runs) except if the checkpoint is the latest archive (and thus still
needed). Checkpoint archives are not considered when comparing archive counts against the
retention limits (--keep-X).

If a prefix is set with -P, then only archives that start with the prefix are considered
for deletion and only those archives count towards the totals specified by the rules.
Otherwise, all archives in the repository are candidates for deletion! There is no
automatic distinction between archives representing different contents. These need to be
distinguished by specifying matching prefixes.

If you have multiple sequences of archives with different data sets (e.g. from different
machines) in one shared repository, use one prune call per data set that matches only the
respective archives using the -P option.

The --keep-within option takes an argument of the form "<int><char>", where char is "H",
"d", "w", "m", "y". For example, --keep-within 2d means to keep all archives that were
created within the past 48 hours. "1m" is taken to mean "31d". The archives kept with
this option do not count towards the totals specified by any other options.

A good procedure is to thin out more and more the older your backups get. As an example,
--keep-daily 7 means to keep the latest backup on each day, up to 7 most recent days with
backups (days without backups do not count). The rules are applied from secondly to
yearly, and backups selected by previous rules do not count towards those of later rules.
The time that each backup starts is used for pruning purposes. Dates and times are
interpreted in the local timezone, and weeks go from Monday to Sunday. Specifying a
negative number of archives to keep means that there is no limit. As of borg 1.2.0, borg
will retain the oldest archive if any of the secondly, minutely, hourly, daily, weekly,
monthly, or yearly rules was not otherwise able to meet its retention target. This enables
the first chronological archive to continue aging until it is replaced by a newer archive
that meets the retention criteria.

The --keep-last N option is doing the same as --keep-secondly N (and it will keep the last
N archives under the assumption that you do not create more than one backup archive in the
same second).

When using --stats, you will get some statistics about how much data was deleted - the
"Deleted data" deduplicated size there is most interesting as that is how much your
repository will shrink. Please note that the "All archives" stats refer to the state
after pruning.

OPTIONS

       See borg-common(1) for common options of Borg commands.

   arguments
       REPOSITORY
              repository to prune

   options
       -n, --dry-run
              do not change repository

       --force
              force  pruning  of corrupted archives, use --force --force in case --force does not
              work.

       -s, --stats
              print statistics for the deleted archive

       --list output verbose list of archives it keeps/prunes

       --keep-within INTERVAL
              keep all archives within this time interval

       --keep-last, --keep-secondly
              number of secondly archives to keep

       --keep-minutely
              number of minutely archives to keep

       -H, --keep-hourly
              number of hourly archives to keep

       -d, --keep-daily
              number of daily archives to keep

       -w, --keep-weekly
              number of weekly archives to keep

       -m, --keep-monthly
              number of monthly archives to keep

       -y, --keep-yearly
              number of yearly archives to keep

       --save-space
              work slower, but using less space

       -c SECONDS, --checkpoint-interval SECONDS
              write checkpoint every SECONDS seconds (Default: 1800)

   Archive filters
       -P PREFIX, --prefix PREFIX
              only consider archive names starting with this prefix. (deprecated)

       -a GLOB, --glob-archives GLOB
              only consider archive names matching the glob. sh:  rules  apply,  see  "borg  help
              patterns".

EXAMPLES

       Be careful, prune is a potentially dangerous command, it will remove backup archives.

       The default of prune is to apply to all archives in the repository unless you restrict its
       operation to a subset of the archives using --glob-archives.  When using  --glob-archives,
       be  careful  to choose a good matching pattern - e.g. do not use "foo*" if you do not also
       want to match "foobar".

       It is strongly recommended to always run prune -v --list --dry-run ...  first so you  will
       see what it would do without it actually doing anything.

          # Keep 7 end of day and 4 additional end of week archives.
          # Do a dry-run without actually deleting anything.
          $ borg prune -v --list --dry-run --keep-daily=7 --keep-weekly=4 /path/to/repo

          # Same as above but only apply to archive names starting with the hostname
          # of the machine followed by a "-" character:
          $ borg prune -v --list --keep-daily=7 --keep-weekly=4 --glob-archives='{hostname}-*' /path/to/repo
          # actually free disk space:
          $ borg compact /path/to/repo

          # Keep 7 end of day, 4 additional end of week archives,
          # and an end of month archive for every month:
          $ borg prune -v --list --keep-daily=7 --keep-weekly=4 --keep-monthly=-1 /path/to/repo

          # Keep all backups in the last 10 days, 4 additional end of week archives,
          # and an end of month archive for every month:
          $ borg prune -v --list --keep-within=10d --keep-weekly=4 --keep-monthly=-1 /path/to/repo

       There is also a visualized prune example in docs/misc/prune-example.txt.

AUTHOR