Merge pull request #2489 from restic/improve-forget-docs

Improve example for forget --keep-daily
This commit is contained in:
rawtaz 2019-11-22 21:20:35 +01:00 committed by GitHub
commit 599831f874
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 60 additions and 6 deletions

View File

@ -213,12 +213,66 @@ All snapshots are evaluated against all matching ``--keep-*`` counts. A
single snapshot on 2017-09-30 (Sat) will count as a daily, weekly and monthly.
Let's explain this with an example: Suppose you have only made a backup
on each Sunday for 12 weeks. Then ``forget --keep-daily 4`` will keep
the last four snapshots for the last four Sundays, but remove the rest.
Only counting the days which have a backup and ignore the ones without
is a safety feature: it prevents restic from removing many snapshots
when no new ones are created. If it was implemented otherwise, running
``forget --keep-daily 4`` on a Friday would remove all snapshots!
on each Sunday for 12 weeks:
.. code-block:: console
$ restic snapshots
repository f00c6e2a opened successfully, password is correct
ID Time Host Tags Paths
---------------------------------------------------------------
0a1f9759 2019-09-01 11:00:00 mopped /home/user/work
46cfe4d5 2019-09-08 11:00:00 mopped /home/user/work
f6b1f037 2019-09-15 11:00:00 mopped /home/user/work
eb430a5d 2019-09-22 11:00:00 mopped /home/user/work
8cf1cb9a 2019-09-29 11:00:00 mopped /home/user/work
5d33b116 2019-10-06 11:00:00 mopped /home/user/work
b9553125 2019-10-13 11:00:00 mopped /home/user/work
e1a7b58b 2019-10-20 11:00:00 mopped /home/user/work
8f8018c0 2019-10-27 11:00:00 mopped /home/user/work
59403279 2019-11-03 11:00:00 mopped /home/user/work
dfee9fb4 2019-11-10 11:00:00 mopped /home/user/work
e1ae2f40 2019-11-17 11:00:00 mopped /home/user/work
---------------------------------------------------------------
12 snapshots
Then ``forget --keep-daily 4`` will keep the last four snapshots for the last
four Sundays, but remove the rest:
.. code-block:: console
$ restic forget --keep-daily 4 --dry-run
repository f00c6e2a opened successfully, password is correct
Applying Policy: keep the last 4 daily snapshots
keep 4 snapshots:
ID Time Host Tags Reasons Paths
-------------------------------------------------------------------------------
8f8018c0 2019-10-27 11:00:00 mopped daily snapshot /home/user/work
59403279 2019-11-03 11:00:00 mopped daily snapshot /home/user/work
dfee9fb4 2019-11-10 11:00:00 mopped daily snapshot /home/user/work
e1ae2f40 2019-11-17 11:00:00 mopped daily snapshot /home/user/work
-------------------------------------------------------------------------------
4 snapshots
remove 8 snapshots:
ID Time Host Tags Paths
---------------------------------------------------------------
0a1f9759 2019-09-01 11:00:00 mopped /home/user/work
46cfe4d5 2019-09-08 11:00:00 mopped /home/user/work
f6b1f037 2019-09-15 11:00:00 mopped /home/user/work
eb430a5d 2019-09-22 11:00:00 mopped /home/user/work
8cf1cb9a 2019-09-29 11:00:00 mopped /home/user/work
5d33b116 2019-10-06 11:00:00 mopped /home/user/work
b9553125 2019-10-13 11:00:00 mopped /home/user/work
e1a7b58b 2019-10-20 11:00:00 mopped /home/user/work
---------------------------------------------------------------
8 snapshots
The result of the ``forget --keep-daily`` operation does not depend on when it
is run, it will only count the days for which a snapshot exists. This is a
safety feature: it prevents restic from removing snapshots when no new ones are
created. Otherwise, running ``forget --keep-daily 4`` on a Friday (without any
snapshot Monday to Thursday) would remove all snapshots!
Another example: Suppose you make daily backups for 100 years. Then
``forget --keep-daily 7 --keep-weekly 5 --keep-monthly 12 --keep-yearly 75``