/volume-backup

docker volume backup & restore utility

Primary LanguageShellMIT LicenseMIT

volume-backup

An utility to backup and restore docker volumes. For more info, read my article on Medium

Note: Make sure no container is using the volume before backup or restore, otherwise your data might be damaged. See Miscellaneous for instructions.

Backup

Backup to standard output

This avoids mounting a second backup volume and allows to redirect it to a file, network, etc.

Syntax:

docker run -v [volume-name]:/volume --rm loomchild/volume-backup backup - > [archive-name]

For example:

docker run -v some_volume:/volume --rm loomchild/volume-backup backup - > some_archive.tar.bz2

will archive volume named some_volume to some_archive.tar.bz2 archive file.

WARNING: This method should not be used under PowerShell on Windows as no usable backup will be generated.

Backup to a file

Syntax:

docker run -v [volume-name]:/volume -v [output-dir]:/backup --rm loomchild/volume-backup backup [archive-name]

For example:

docker run -v some_volume:/volume -v /tmp:/backup --rm loomchild/volume-backup backup some_archive

will archive volume named some_volume to /tmp/some_archive.tar.bz2 archive file.

Restore

WARNING: This operation will delete all contents of the volume

Restore from standard input

This avoids mounting a second backup volume.

Note: Don't forget the -i switch for interactive operation.

Syntax:

cat [archive-name] | docker run -i -v [volume-name]:/volume --rm loomchild/volume-backup restore -

For example:

cat some_archive.tar.bz2 | docker run -i -v some_volume:/volume --rm loomchild/volume-backup restore -

will clean and restore volume named some_volume from some_archive.tar.bz2 archive file.

Restore from a file

Syntax:

docker run -v [volume-name]:/volume -v [output-dir]:/backup --rm loomchild/volume-backup restore [archive-name]

For example:

docker run -v some_volume:/volume -v /tmp:/backup --rm loomchild/volume-backup restore some_archive

will clean and restore volume named some_volume from /tmp/some_archive.tar.bz2 archive file.

Copy volume between hosts

One good example of how you can use the output to stdout would be directly migrating the volume to a new host

Syntax:

docker run -v [volume-name]:/volume --rm loomchild/volume-backup backup - |\
     ssh [receiver] docker run -i -v [volume-name]:/volume --rm loomchild/volume-backup restore -

Note: In case there are no traffic limitations between the hosts you can trade CPU time for bandwidth by turning off compression as shown in the example below.

For example:

docker run -v some_volume:/volume --rm loomchild/volume-backup backup -c none - |\
     ssh user@new.machine docker run -i -v some_volume:/volume --rm loomchild/volume-backup restore -c none -

Miscellaneous

  1. Upgrade / update volume-backup

    docker pull loomchild/volume-backup

  2. Find all containers using a volume (to stop them before backing-up)

    docker ps -a --filter volume=[volume-name]

  3. Exclude some files from the backup and send the archive to stdout

    docker run -v [volume-name]:/volume --rm loomchild/volume-backup backup -e [excluded-glob] - > [archive-name]

  4. Use different compression algorithm for better performance

    docker run -v [volume-name]:/volume --rm loomchild/volume-backup backup -c gz - > [archive-name]

  5. Show simple progress indicator using verbose -v flag (works both for backup and restore)

    docker run -v [volume-name]:/volume --rm loomchild/volume-backup backup -v > [archive-name]