borg analyze

borg [common options] analyze [options]

Common options
Archive filters — Archive filters can be applied to repository targets.
	-a PATTERN, --match-archives PATTERN	only consider archives matching all patterns. See “borg help match-archives”.
	--sort-by KEYS	Comma-separated list of sorting keys; valid keys are: timestamp, archive, name, id, tags, host, user; default is: timestamp
	--first N	consider the first N archives after other filters are applied
	--last N	consider the last N archives after other filters are applied
	--oldest TIMESPAN	consider archives between the oldest archive’s timestamp and (oldest + TIMESPAN), e.g., 7d or 12m.
	--newest TIMESPAN	consider archives between the newest archive’s timestamp and (newest - TIMESPAN), e.g., 7d or 12m.
	--older TIMESPAN	consider archives older than (now - TIMESPAN), e.g., 7d or 12m.
	--newer TIMESPAN	consider archives newer than (now - TIMESPAN), e.g., 7d or 12m.

Description

Analyze archives to find “hot spots”.

borg analyze relies on the usual archive matching options to select the archives that should be considered for analysis (e.g. -a series_name). Then it iterates over all matching archives, over all contained files, and collects information about chunks stored in all directories it encounters.

It considers chunk IDs and their plaintext sizes (we do not have the compressed size in the repository easily available) and adds up the sizes of added and removed chunks per direct parent directory, and outputs a list of “directory: size”.

You can use that list to find directories with a lot of “activity” — maybe some of these are temporary or cache directories you forgot to exclude.

To avoid including these unwanted directories in your backups, you can carefully exclude them in borg create (for future backups) or use borg recreate to recreate existing archives without them.