NAME

       borg-compact - Collect garbage in repository

SYNOPSIS

       borg [common options] compact [options]

DESCRIPTION

       Free repository space by deleting unused chunks.

       borg  compact  analyzes  all  existing  archives  to  find out which repository objects are actually used
       (referenced). It then deletes all unused objects from the repository to free space.

       Unused objects may result from:

       • borg delete or prune usage

       • interrupted backups (maybe retry the backup first before running compact)

       • backup of source files that had an I/O error in the middle of their contents and that were skipped  due
         to this

       • corruption of the repository (e.g. the archives directory having lost entries, see notes below)

       You usually don't want to run borg compact after every write operation, but either regularly (e.g. once a
       month, possibly together with borg check) or when disk space needs to be freed.

       Important:

       After  compacting  it  is  no  longer  possible  to  use borg undelete to recover previously soft-deleted
       archives.

       borg compact might also delete data from archives that were "lost" due to archives directory  corruption.
       Such  archives  could  potentially  be restored with borg check --find-lost-archives [--repair], which is
       slow. You therefore might not want to do that unless there are signs of lost archives (e.g.  when  seeing
       fatal errors when creating backups or when archives are missing in borg repo-list).

       When  giving  the  --stats  option,  borg  will internally list all repository objects to determine their
       existence AND stored size. It will build a fresh chunks index from that information and cache it  in  the
       repository.  For  some types of repositories, this might be very slow. It will tell you the sum of stored
       object sizes, before and after compaction.

       Without --stats, borg will rely on the cached chunks index to determine existing object IDs (but there is
       no stored size information in the index, thus it can't compute before/after compaction size statistics).

OPTIONS

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

   options
       -n, --dry-run
              do nothing

       -s, --stats
              print statistics (might be much slower)

EXAMPLES

          # compact segments and free repo disk space
          $ borg compact

SEE ALSO

       borg-common(1)

AUTHOR

       The Borg Collective

                                                   2025-06-23                                    BORG-COMPACT(1)