btrbk/btrbk.conf.example

#
# Example btrbk configuration file
#
#
# Please refer to the btrbk.conf(5) man-page for a complete
# description of all configuration options.
# For more examples, see README.md included with this package.
#
#   btrbk.conf(5): <https://digint.ch/btrbk/doc/btrbk.conf.5.html>
#   README.md:     <https://digint.ch/btrbk/doc/readme.html>
#
# Note that the options can be overridden per volume/subvolume/target
# in the corresponding sections.
#


# Enable transaction log
transaction_log            /var/log/btrbk.log

# Enable stream buffer. Adding a buffer between the sending and
# receiving side is generally a good idea.
# NOTE: If enabled, make sure to install the "mbuffer" package!
stream_buffer              256m

# Directory in which the btrfs snapshots are created. Relative to
# <volume-directory> of the volume section.
# If not set, the snapshots are created in <volume-directory>.
#
# If you want to set a custom name for the snapshot (and backups),
# use the "snapshot_name" option within the subvolume section.
#
# NOTE: btrbk does not autmatically create this directory, and the
# snapshot creation will fail if it is not present.
#
snapshot_dir               _btrbk_snap

# Always create snapshots. Set this to "ondemand" to only create
# snapshots if the target volume is reachable. Set this to "no" if
# snapshot creation is done by another instance of btrbk.
#snapshot_create            always

# Perform incremental backups (set to "strict" if you want to prevent
# creation of non-incremental backups if no parent is found).
#incremental                yes

# Specify after what time (in full hours after midnight) backups/
# snapshots are considered as a daily backup/snapshot
#preserve_hour_of_day       0

# Specify on which day of week weekly/monthly backups are to be
# preserved.
#preserve_day_of_week       sunday

# Preserve all snapshots for a minimum period of time.
#snapshot_preserve_min      1d

# Retention policy for the source snapshots.
#snapshot_preserve          <NN>h <NN>d <NN>w <NN>m <NN>y

# Preserve all backup targets for a minimum period of time.
#target_preserve_min        no

# Retention policy for backup targets:
#target_preserve            <NN>h <NN>d <NN>w <NN>m <NN>y

# Retention policy for archives ("btrbk archive" command):
#archive_preserve_min       no
#archive_preserve           <NN>h <NN>d <NN>w <NN>m <NN>y

# Specify SSH private key for "ssh://" volumes / targets:
#ssh_identity               /etc/btrbk/ssh/id_ed25519
#ssh_user                   root
#ssh_compression            no
#ssh_cipher_spec            default

# Enable compression for remote btrfs send/receive operations:
#stream_compress            no
#stream_compress_level      default
#stream_compress_threads    default

# Enable lock file support: Ensures that only one instance of btrbk
# can be run at a time.
#lockfile                   /var/lock/btrbk.lock

# Don't wait for transaction commit on deletion. Set this to "after"
# or "each" to make sure the deletion of subvolumes is committed to
# disk when btrbk terminates.
#btrfs_commit_delete        no


#
# Volume section: "volume <volume-directory>"
#
#   <volume-directory>  Directory of a btrfs volume (or subvolume)
#                       containing the subvolume to be backuped
#                       (usually the mount-point of a btrfs filesystem
#                       mounted with subvolid=5 option)
#
# Subvolume section: "subvolume <subvolume-name>"
#
#   <subvolume-name>    Subvolume to be backuped, relative to
#                       <volume-directory> in volume section.
#
# Target section: "target <type> <volume-directory>"
#
#   <type>              (optional) type, defaults to "send-receive".
#   <volume-directory>  Directory of a btrfs volume (or subvolume)
#                       receiving the backups.
#
# NOTE: The parser does not care about indentation, this is only for
# human readability. The options always apply to the last section
# encountered, overriding the corresponding option of the upper
# section. This means that the global options must be set before any
# "volume" section.
#


#
# Example configuration:
#
snapshot_preserve_min   2d
snapshot_preserve       14d

target_preserve_min     no
target_preserve         20d 10w *m

archive_preserve_min    latest
archive_preserve        12m 10y

# Backup to external disk mounted on /mnt/btr_backup
volume /mnt/btr_pool
  # no action if external disk is not attached
  snapshot_create  ondemand

  # propagates to all subvolume sections:
  target /mnt/btr_backup/_btrbk

  subvolume  root_gentoo
  subvolume  kvm
    # use different retention policy for kvm backups
    target_preserve     7d 4w


# Backup to external disk as well as some remote host
volume /mnt/btr_data
  subvolume  home
    # always create snapshot, even if targets are unreachable
    snapshot_create  always
    target /mnt/btr_backup/_btrbk
    target ssh://backup.my-remote-host.com/mnt/btr_backup


# Backup from remote host, with different naming
volume ssh://my-remote-host.com/mnt/btr_pool
  subvolume data_0
    snapshot_dir   snapshots/btrbk
    snapshot_name  data_main
    target /mnt/btr_backup/_btrbk/my-remote-host.com


# Resume backups from remote host which runs its own btrbk instance
# creating snapshots for "home" in "/mnt/btr_pool/btrbk_snapshots".
volume ssh://my-remote-host.com/mnt/btr_pool
  snapshot_dir           btrbk_snapshots
  snapshot_create        no
  snapshot_preserve_min  all
  subvolume home
    target /mnt/btr_backup/_btrbk/my-remote-host.com