zfs-snap-manager

This role installs and configures zfs-snap-manager, a tool to automatically create, replicate and destroy ZFS snapshots.

Requirements

An apt-based distribution (target and controller as well). On the controlling machine, git has to be installed. Obviously, any ZFS filesystems that should be snapshotted must exist.

Role Variables

Name	Mandatory / Default	Description
global_cache_dir	$ansible_env.HOME/.cache	cache directory to clone git repo to
zfs_snap_manager_version	0.2.0	zfs-snap-manager version to use
zfs_parent_fs		Parent pool or filesystem (optionally prepended to all datasets)
zfs_filesystems	[]	List of filesystems to be snapshotted. Snapshots can be configured using the dict item snapshots. For its content see [snapshot configuration](#snapshot configuration)
zvols	[]	List of zvols to be snapshotted. Snapshots can be configured using the dict item snapshots. For its content see [snapshot configuration](#snapshot configuration)

Defaults for the snapshot dict can be set by prepending zfs_snapshot_default_, e.g. zfs_snapshot_default_replicate_endpoint.

Snapshot configuration

Name	Default	Description
mountpoint	(omitted)	Points to the location to which the dataset is mounted. Only needed when time = trigger
time	04:00	Can be either a timestamp in 24h notation after which a snapshot needs to be taken. It can also be trigger indicating that it will take a snapshot as soon as a file with name .trigger is found in the dataset's mountpoint. This can be used in case data is for example rsynced to the dataset.
snapshot	True	(boolean) Indicates whether a snapshot should be taken or not. It might be possible that only cleaning needs to be executed if this dataset is actually a replication target for another machine.
replicate_endpoint	(omitted)	Can be left empty if replicating on localhost (e.g. copying snapshots to other pool). Should be omitted if no replication is required.
replicate_target	(omitted)	The target to which the snapshots should be send. Should be omitted if no replication is required or a replication_source is specified.
replicate_source	(omitted)	The source from which to pull the snapshots to receive onto the local dataset. Should be omitted if no replication is required or a replication_target is specified.
compression	(omitted)	Indicates the compression program to pipe remote replicated snapshots through (for use in low-bandwidth setups.) The compression utility should accept standard compression flags (-c for standard output, -d for decompress.)
schema	7d3w11m4y	In case the snapshots should be cleaned, this is the schema the manager will use to clean.
preexec	(omitted)	A command that will be executed, before snapshot/replication. Should be omitted if nothing should be executed
postexec	(omitted)	A command that will be executed, after snapshot/replication, but before the cleanup. Should be omitted if nothing should be executed

Note that recursive snapshotting is not supported by zfs-snap-manager. For more information on configuration and constraints thereof, consider reading the documentation at zfs-snap-manager.

Example Playbook

zfs_parent_fs: rpool
zfs_filesystems:
  - name: test
  - name: zroot
    snapshots:
      time: "14:00"
      schema: 10d5w1m10y
      replicate_endpoint: "ssh -p 2345 my.remote.server.org"
      replicate_target: tank/backups/rootfs
      compression: gzip
  - name: data
    snapshots:
      mountpoint: /mnt/data
      time: trigger
      snapshot: True
      schema: 5d0w0m0y
      preexec: "echo \"starting\" | mail somebody@example.com"
      postexec: "echo \"finished\" | mail somebody@exampe.com"
  - name: zvol
    snapshots:
      time: "22:00"
  - name: backups/data
    snapshots:
      mountpoint: "/mnt/backups/data"
      snapshot: False
      replicate_endpoint: "ssh other.remote.server.org"
      replicate_source: zpool/data

Results

rpool/test will be snapshotted locally daily at 04:00 and snapshots will be cleaned up with the default schema 7d3w11m4y.

rpool/zroot will be snapshotted at 14:00 with schema 10d5w1m10y and replicated to an example host (to destination dataset tank/backups/rootfs using gzip as compression).

rpool/data will be snapshotted by placing a .trigger file in /mnt/data. Only snapshots created in the last 5 days are kept. Before and after snapshotting, an email will be sent.

rpool/zvol is being snapshotted with the default schema 7d3w11m4y every day at 22:00.

rpool/backups/data will not be snapshotted but pulls snapshots from zpool/data residing at remote host other.remote.server.org to the local dataset of this name.

License

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Author Information

• Michel Weitbrecht (SlothOfAnarchy) michel.weitbrecht@stuvus.uni-stuttgart.de