mirror of
https://github.com/octoleo/restic.git
synced 2024-11-22 12:55:18 +00:00
285 lines
12 KiB
ReStructuredText
285 lines
12 KiB
ReStructuredText
..
|
||
Normally, there are no heading levels assigned to certain characters as the structure is
|
||
determined from the succession of headings. However, this convention is used in Python’s
|
||
Style Guide for documenting which you may follow:
|
||
|
||
# with overline, for parts
|
||
* for chapters
|
||
= for sections
|
||
- for subsections
|
||
^ for subsubsections
|
||
" for paragraphs
|
||
|
||
#########################
|
||
Removing backup snapshots
|
||
#########################
|
||
|
||
All backup space is finite, so restic allows removing old snapshots.
|
||
This can be done either manually (by specifying a snapshot ID to remove)
|
||
or by using a policy that describes which snapshots to forget. For all
|
||
remove operations, two commands need to be called in sequence:
|
||
``forget`` to remove a snapshot and ``prune`` to actually remove the
|
||
data that was referenced by the snapshot from the repository. This can
|
||
be automated with the ``--prune`` option of the ``forget`` command,
|
||
which runs ``prune`` automatically if snapshots have been removed.
|
||
|
||
.. Warning::
|
||
|
||
Pruning snapshots can be a very time-consuming process, taking nearly
|
||
as long as backups themselves. During a prune operation, the index is
|
||
locked and backups cannot be completed. Performance improvements are
|
||
planned for this feature.
|
||
|
||
It is advisable to run ``restic check`` after pruning, to make sure
|
||
you are alerted, should the internal data structures of the repository
|
||
be damaged.
|
||
|
||
Remove a single snapshot
|
||
************************
|
||
|
||
The command ``snapshots`` can be used to list all snapshots in a
|
||
repository like this:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic -r /srv/restic-repo snapshots
|
||
enter password for repository:
|
||
ID Date Host Tags Directory
|
||
----------------------------------------------------------------------
|
||
40dc1520 2015-05-08 21:38:30 kasimir /home/user/work
|
||
79766175 2015-05-08 21:40:19 kasimir /home/user/work
|
||
bdbd3439 2015-05-08 21:45:17 luigi /home/art
|
||
590c8fc8 2015-05-08 21:47:38 kazik /srv
|
||
9f0bc19e 2015-05-08 21:46:11 luigi /srv
|
||
|
||
In order to remove the snapshot of ``/home/art``, use the ``forget``
|
||
command and specify the snapshot ID on the command line:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic -r /srv/restic-repo forget bdbd3439
|
||
enter password for repository:
|
||
removed snapshot d3f01f63
|
||
|
||
Afterwards this snapshot is removed:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic -r /srv/restic-repo snapshots
|
||
enter password for repository:
|
||
ID Date Host Tags Directory
|
||
----------------------------------------------------------------------
|
||
40dc1520 2015-05-08 21:38:30 kasimir /home/user/work
|
||
79766175 2015-05-08 21:40:19 kasimir /home/user/work
|
||
590c8fc8 2015-05-08 21:47:38 kazik /srv
|
||
9f0bc19e 2015-05-08 21:46:11 luigi /srv
|
||
|
||
But the data that was referenced by files in this snapshot is still
|
||
stored in the repository. To cleanup unreferenced data, the ``prune``
|
||
command must be run:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic -r /srv/restic-repo prune
|
||
enter password for repository:
|
||
|
||
counting files in repo
|
||
building new index for repo
|
||
[0:00] 100.00% 22 / 22 files
|
||
repository contains 22 packs (8512 blobs) with 100.092 MiB bytes
|
||
processed 8512 blobs: 0 duplicate blobs, 0B duplicate
|
||
load all snapshots
|
||
find data that is still in use for 1 snapshots
|
||
[0:00] 100.00% 1 / 1 snapshots
|
||
found 8433 of 8512 data blobs still in use
|
||
will rewrite 3 packs
|
||
creating new index
|
||
[0:00] 86.36% 19 / 22 files
|
||
saved new index as 544a5084
|
||
done
|
||
|
||
Afterwards the repository is smaller.
|
||
|
||
You can automate this two-step process by using the ``--prune`` switch
|
||
to ``forget``:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic forget --keep-last 1 --prune
|
||
snapshots for host mopped, directories /home/user/work:
|
||
|
||
keep 1 snapshots:
|
||
ID Date Host Tags Directory
|
||
----------------------------------------------------------------------
|
||
4bba301e 2017-02-21 10:49:18 mopped /home/user/work
|
||
|
||
remove 1 snapshots:
|
||
ID Date Host Tags Directory
|
||
----------------------------------------------------------------------
|
||
8c02b94b 2017-02-21 10:48:33 mopped /home/user/work
|
||
|
||
1 snapshots have been removed, running prune
|
||
counting files in repo
|
||
building new index for repo
|
||
[0:00] 100.00% 37 / 37 packs
|
||
repository contains 37 packs (5521 blobs) with 151.012 MiB bytes
|
||
processed 5521 blobs: 0 duplicate blobs, 0B duplicate
|
||
load all snapshots
|
||
find data that is still in use for 1 snapshots
|
||
[0:00] 100.00% 1 / 1 snapshots
|
||
found 5323 of 5521 data blobs still in use, removing 198 blobs
|
||
will delete 0 packs and rewrite 27 packs, this frees 22.106 MiB
|
||
creating new index
|
||
[0:00] 100.00% 30 / 30 packs
|
||
saved new index as b49f3e68
|
||
done
|
||
|
||
Removing snapshots according to a policy
|
||
****************************************
|
||
|
||
Removing snapshots manually is tedious and error-prone, therefore restic
|
||
allows specifying which snapshots should be removed automatically
|
||
according to a policy. You can specify how many hourly, daily, weekly,
|
||
monthly and yearly snapshots to keep, any other snapshots are removed.
|
||
The most important command-line parameter here is ``--dry-run`` which
|
||
instructs restic to not remove anything but print which snapshots would
|
||
be removed.
|
||
|
||
When ``forget`` is run with a policy, restic loads the list of all
|
||
snapshots, then groups these by host name and list of directories. The grouping
|
||
options can be set with ``--group-by``, to only group snapshots by paths and
|
||
tags use ``--group-by paths,tags``. The policy is then applied to each group of
|
||
snapshots separately. This is a safety feature.
|
||
|
||
The ``forget`` command accepts the following parameters:
|
||
|
||
- ``--keep-last n`` never delete the ``n`` last (most recent) snapshots
|
||
- ``--keep-hourly n`` for the last ``n`` hours in which a snapshot was
|
||
made, keep only the last snapshot for each hour.
|
||
- ``--keep-daily n`` for the last ``n`` days which have one or more
|
||
snapshots, only keep the last one for that day.
|
||
- ``--keep-weekly n`` for the last ``n`` weeks which have one or more
|
||
snapshots, only keep the last one for that week.
|
||
- ``--keep-monthly n`` for the last ``n`` months which have one or more
|
||
snapshots, only keep the last one for that month.
|
||
- ``--keep-yearly n`` for the last ``n`` years which have one or more
|
||
snapshots, only keep the last one for that year.
|
||
- ``--keep-tag`` keep all snapshots which have all tags specified by
|
||
this option (can be specified multiple times).
|
||
- ``--keep-within duration`` keep all snapshots which have been made within
|
||
the duration of the latest snapshot. ``duration`` needs to be a number of
|
||
years, months, days, and hours, e.g. ``2y5m7d3h`` will keep all snapshots
|
||
made in the two years, five months, seven days, and three hours before the
|
||
latest snapshot.
|
||
|
||
Multiple policies will be ORed together so as to be as inclusive as possible
|
||
for keeping snapshots.
|
||
|
||
Additionally, you can restrict removing snapshots to those which have a
|
||
particular hostname with the ``--hostname`` parameter, or tags with the
|
||
``--tag`` option. When multiple tags are specified, only the snapshots
|
||
which have all the tags are considered. For example, the following command
|
||
removes all but the latest snapshot of all snapshots that have the tag ``foo``:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic forget --tag foo --keep-last 1
|
||
|
||
This command removes all but the last snapshot of all snapshots that have
|
||
either the ``foo`` or ``bar`` tag set:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic forget --tag foo --tag bar --keep-last 1
|
||
|
||
To only keep the last snapshot of all snapshots with both the tag ``foo`` and
|
||
``bar`` set use:
|
||
|
||
.. code-block:: console
|
||
|
||
$ restic forget --tag foo,bar --keep-last 1
|
||
|
||
All the ``--keep-*`` options above only count
|
||
hours/days/weeks/months/years which have a snapshot, so those without a
|
||
snapshot are ignored.
|
||
|
||
For safety reasons, restic refuses to act on an "empty" policy. For example,
|
||
if one were to specify ``--keep-last 0`` to forget *all* snapshots in the
|
||
repository, restic will respond that no snapshots will be removed. To delete
|
||
all snapshots, use ``--keep-last 1`` and then finally remove the last
|
||
snapshot ID manually (by passing the ID to ``forget``).
|
||
|
||
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:
|
||
|
||
.. 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``
|
||
will keep the most recent 7 daily snapshots, then 4 (remember, 7 dailies
|
||
already include a week!) last-day-of-the-weeks and 11 or 12
|
||
last-day-of-the-months (11 or 12 depends if the 5 weeklies cross a month).
|
||
And finally 75 last-day-of-the-year snapshots. All other snapshots are
|
||
removed.
|
||
|