restic/doc/045_working_with_repos.rst

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#########################
Working with repositories
#########################

Listing all snapshots
=====================

Now, you can list all the snapshots stored in the repository:

.. 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

You can filter the listing by directory path:

.. code-block:: console

    $ restic -r /srv/restic-repo snapshots --path="/srv"
    enter password for repository:
    ID        Date                 Host    Tags   Directory
    ----------------------------------------------------------------------
    590c8fc8  2015-05-08 21:47:38  kazik          /srv
    9f0bc19e  2015-05-08 21:46:11  luigi          /srv

Or filter by host:

.. code-block:: console

    $ restic -r /srv/restic-repo snapshots --host luigi
    enter password for repository:
    ID        Date                 Host    Tags   Directory
    ----------------------------------------------------------------------
    bdbd3439  2015-05-08 21:45:17  luigi          /home/art
    9f0bc19e  2015-05-08 21:46:11  luigi          /srv

Combining filters is also possible.

Furthermore you can group the output by the same filters (host, paths, tags):

.. code-block:: console

    $ restic -r /srv/restic-repo snapshots --group-by host

    enter password for repository:
    snapshots for (host [kasimir])
    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
    2 snapshots
    snapshots for (host [luigi])
    ID        Date                 Host    Tags   Directory
    ----------------------------------------------------------------------
    bdbd3439  2015-05-08 21:45:17  luigi          /home/art
    9f0bc19e  2015-05-08 21:46:11  luigi          /srv
    2 snapshots
    snapshots for (host [kazik])
    ID        Date                 Host    Tags   Directory
    ----------------------------------------------------------------------
    590c8fc8  2015-05-08 21:47:38  kazik          /srv
    1 snapshots


Copying snapshots between repositories
======================================

In case you want to transfer snapshots between two repositories, for
example from a local to a remote repository, you can use the ``copy`` command:

.. code-block:: console

    $ restic -r /srv/restic-repo copy --repo2 /srv/restic-repo-copy
    repository d6504c63 opened successfully, password is correct
    repository 3dd0878c opened successfully, password is correct

    snapshot 410b18a2 of [/home/user/work] at 2020-06-09 23:15:57.305305 +0200 CEST)
      copy started, this may take a while...
    snapshot 7a746a07 saved

    snapshot 4e5d5487 of [/home/user/work] at 2020-05-01 22:44:07.012113 +0200 CEST)
    skipping snapshot 4e5d5487, was already copied to snapshot 50eb62b7

The example command copies all snapshots from the source repository
``/srv/restic-repo`` to the destination repository ``/srv/restic-repo-copy``.
Snapshots which have previously been copied between repositories will
be skipped by later copy runs.

.. note:: Note that this process will have to read (download) and write (upload) the
    entire snapshot(s) due to the different encryption keys used in the source and
    destination repository. Also, the transferred files are not re-chunked, which
    may break deduplication between files already stored in the destination repo
    and files copied there using this command. See the next section for how to avoid
    this problem.

For the destination repository ``--repo2`` the password can be read from
a file ``--password-file2`` or from a command ``--password-command2``.
Alternatively the environment variables ``$RESTIC_PASSWORD_COMMAND2`` and
``$RESTIC_PASSWORD_FILE2`` can be used. It is also possible to directly
pass the password via ``$RESTIC_PASSWORD2``. The key which should be used
for decryption can be selected by passing its ID via the flag ``--key-hint2``
or the environment variable ``$RESTIC_KEY_HINT2``.

In case the source and destination repository use the same backend, then
configuration options and environment variables to configure the backend
apply to both repositories. For example it might not be possible to specify
different accounts for the source and destination repository. You can
avoid this limitation by using the rclone backend along with remotes which
are configured in rclone.

The list of snapshots to copy can be filtered by host, path in the backup
and / or a comma-separated tag list:

.. code-block:: console

    $ restic -r /srv/restic-repo copy --repo2 /srv/restic-repo-copy --host luigi --path /srv --tag foo,bar

It is also possible to explicitly specify the list of snapshots to copy, in
which case only these instead of all snapshots will be copied:

.. code-block:: console

    $ restic -r /srv/restic-repo copy --repo2 /srv/restic-repo-copy 410b18a2 4e5d5487 latest


Ensuring deduplication for copied snapshots
-------------------------------------------

Even though the copy command can transfer snapshots between arbitrary repositories,
deduplication between snapshots from the source and destination repository may not work.
To ensure proper deduplication, both repositories have to use the same parameters for
splitting large files into smaller chunks, which requires additional setup steps. With
the same parameters restic will for both repositories split identical files into
identical chunks and therefore deduplication also works for snapshots copied between
these repositories.

The chunker parameters are generated once when creating a new (destination) repository.
That is for a copy destination repository we have to instruct restic to initialize it
using the same chunker parameters as the source repository:

.. code-block:: console

    $ restic -r /srv/restic-repo-copy init --repo2 /srv/restic-repo --copy-chunker-params

Note that it is not possible to change the chunker parameters of an existing repository.


Checking integrity and consistency
==================================

Imagine your repository is saved on a server that has a faulty hard
drive, or even worse, attackers get privileged access and modify the
files in your repository with the intention to make you restore
malicious data:

.. code-block:: console

    $ echo "boom" > /srv/restic-repo/index/de30f3231ca2e6a59af4aa84216dfe2ef7339c549dc11b09b84000997b139628

Trying to restore a snapshot which has been modified as shown above
will yield an error:

.. code-block:: console

    $ restic -r /srv/restic-repo --no-cache restore c23e491f --target /tmp/restore-work
    ...
    Fatal: unable to load index de30f323: load <index/de30f3231c>: invalid data returned

In order to detect these things before they become a problem, it's a
good idea to regularly use the ``check`` command to test whether your
repository is healthy and consistent, and that your precious backup
data is unharmed. There are two types of checks that can be performed:

- Structural consistency and integrity, e.g. snapshots, trees and pack files (default)
- Integrity of the actual data that you backed up (enabled with flags, see below)

To verify the structure of the repository, issue the ``check`` command.
If the repository is damaged like in the example above, ``check`` will
detect this and yield the same error as when you tried to restore:

.. code-block:: console

    $ restic -r /srv/restic-repo check
    ...
    load indexes
    error: error loading index de30f323: load <index/de30f3231c>: invalid data returned
    Fatal: LoadIndex returned errors

If the repository structure is intact, restic will show that no errors were found:

.. code-block:: console

    $ restic -r /src/restic-repo check
    ...
    load indexes
    check all packs
    check snapshots, trees and blobs
    no errors were found

By default, the ``check`` command does not verify that the actual pack files
on disk in the repository are unmodified, because doing so requires reading
a copy of every pack file in the repository. To tell restic to also verify the
integrity of the pack files in the repository, use the ``--read-data`` flag:

.. code-block:: console

    $ restic -r /srv/restic-repo check --read-data
    ...
    load indexes
    check all packs
    check snapshots, trees and blobs
    read all data
    [0:00] 100.00%  3 / 3 items
    duration: 0:00
    no errors were found

.. note:: Since ``--read-data`` has to download all pack files in the
    repository, beware that it might incur higher bandwidth costs than usual
    and also that it takes more time than the default ``check``.

Alternatively, use the ``--read-data-subset=n/t`` parameter to check only a
subset of the repository pack files at a time. The parameter takes two values,
``n`` and ``t``. When the check command runs, all pack files in the repository
are logically divided in ``t`` (roughly equal) groups, and only files that
belong to group number ``n`` are checked. For example, the following commands
check all repository pack files over 5 separate invocations:

.. code-block:: console

    $ restic -r /srv/restic-repo check --read-data-subset=1/5
    $ restic -r /srv/restic-repo check --read-data-subset=2/5
    $ restic -r /srv/restic-repo check --read-data-subset=3/5
    $ restic -r /srv/restic-repo check --read-data-subset=4/5
    $ restic -r /srv/restic-repo check --read-data-subset=5/5