Retention and maintenance

Retention

A retention policy keeps the last commit of each calendar hour, day, week or month. Each --keep bracket covers a number of these periods. The brackets run back from now one after the other, newest first:

goback set retention home \
  --keep hourly=336 --keep daily=60 --keep weekly=12 --keep monthly

With this policy, the set keeps one commit per hour for the last 336 hours, then one per day for the 60 days before that, then one per week for 12 weeks. Older commits are kept one per month. The last bracket can leave out its count to keep its commits forever.

--keep-last <n> also keeps the newest n commits. --keep-within <duration> keeps every commit younger than that. Without a set name, set retention shows or changes the store’s default policy. --inherit removes a set’s own policy, so the store’s default applies again.

If neither the set nor the store has a policy, goback uses a built-in one: the brackets above, plus the newest commit.

What happens to a commit

Stage	Undo with
deleted by hand: waits in the trash (--trash-days)	commit undelete
expired by the policy: removed from the set at the next maintain run	commit unretire, until collected
no live commit or pin reaches its objects: garbage collected	can’t be undone

goback pin keeps a commit regardless of retention.

Maintenance

Without a server, run goback maintain from cron:

0 * * * * goback maintain

Each run removes the commits that retention or the trash let go, compacts small archives and does other housekeeping. When the last garbage collection is older than --gc-interval, the run also collects garbage. A server does all of this on its own schedule.

Integrity

Command	Does
goback scrub	rehash every stored object
goback repair	rewrite the archives holding corrupt ones
goback fix	rebuild the index from the store

See Snapshot lifecycle and Garbage collection.