diff --git a/README.md b/README.md index 182275c..b4ee22d 100644 --- a/README.md +++ b/README.md @@ -279,6 +279,19 @@ root@ws1:~# zfs-autobackup test --verbose This also allows you to make several snapshots during the day, but only backup the data at night when the server is not busy. +## Running custom commands before and after snapshotting + +If you need, e.g. to quiesce a couple of mysql databases to make on-disk data consistent before snapshotting, try: + +```sh +zfs-autobackup \ + --pre-snapshot-cmd 'daemon -f jexec mysqljail1 mysql -s -e "set autocommit=0;flush logs;flush tables with read lock;\\! echo \$\$ > /tmp/mysql_lock.pid && sleep 60"' \ + --pre-snapshot-cmd 'daemon -f jexec mysqljail2 mysql -s -e "set autocommit=0;flush logs;flush tables with read lock;\\! echo \$\$ > /tmp/mysql_lock.pid && sleep 60"' \ + --post-snapshot-cmd 'pkill -F /jails/mysqljail1/tmp/mysql_lock.pid' \ + --post-snapshot-cmd 'pkill -F /jails/mysqljail2/tmp/mysql_lock.pid' \ + test +``` + ## Thinning out obsolete snapshots The thinner is the thing that destroys old snapshots on the source and target. @@ -493,7 +506,8 @@ Look in man ssh_config for many more options. ```console usage: zfs-autobackup [-h] [--ssh-config CONFIG-FILE] [--ssh-source USER@HOST] [--ssh-target USER@HOST] [--keep-source SCHEDULE] - [--keep-target SCHEDULE] [--other-snapshots] + [--keep-target SCHEDULE] [--pre-snapshot-cmd COMMAND] + [--post-snapshot-cmd COMMAND] [--other-snapshots] [--no-snapshot] [--no-send] [--no-thinning] [--no-holds] [--min-change BYTES] [--allow-empty] [--ignore-replicated] [--strip-path N] @@ -531,6 +545,12 @@ optional arguments: --keep-target SCHEDULE Thinning schedule for old target snapshots. Default: 10,1d1w,1w1m,1m1y + --pre-snapshot-cmd COMMAND + Run COMMAND before snapshotting (can be used multiple + times. + --post-snapshot-cmd COMMAND + Run COMMAND after snapshotting (can be used multiple + times. --other-snapshots Send over other snapshots as well, not just the ones created by this tool. --no-snapshot Don't create new snapshots (useful for finishing diff --git a/zfs_autobackup/ZfsAutobackup.py b/zfs_autobackup/ZfsAutobackup.py index 3caded7..bf3e8f3 100644 --- a/zfs_autobackup/ZfsAutobackup.py +++ b/zfs_autobackup/ZfsAutobackup.py @@ -45,6 +45,10 @@ class ZfsAutobackup: help='Target ZFS filesystem (optional: if not specified, zfs-autobackup will only operate ' 'as snapshot-tool on source)') + parser.add_argument('--pre-snapshot-cmd', metavar="COMMAND", default=[], action='append', + help='Run COMMAND before snapshotting (can be used multiple times.') + parser.add_argument('--post-snapshot-cmd', metavar="COMMAND", default=[], action='append', + help='Run COMMAND after snapshotting (can be used multiple times.') parser.add_argument('--other-snapshots', action='store_true', help='Send over other snapshots as well, not just the ones created by this tool.') parser.add_argument('--no-snapshot', action='store_true', @@ -506,7 +510,9 @@ class ZfsAutobackup: if not self.args.no_snapshot: self.set_title("Snapshotting") source_node.consistent_snapshot(source_datasets, source_node.new_snapshotname(), - min_changed_bytes=self.args.min_change) + min_changed_bytes=self.args.min_change, + pre_snapshot_cmd=self.args.pre_snapshot_cmd, + post_snapshot_cmd=self.args.post_snapshot_cmd) ################# sync # if target is specified, we sync the datasets, otherwise we just thin the source. (e.g. snapshot mode) diff --git a/zfs_autobackup/ZfsNode.py b/zfs_autobackup/ZfsNode.py index 5243cfa..eb1cf84 100644 --- a/zfs_autobackup/ZfsNode.py +++ b/zfs_autobackup/ZfsNode.py @@ -1,6 +1,7 @@ # python 2 compatibility from __future__ import print_function import re +import shlex import subprocess import sys import time @@ -161,7 +162,7 @@ class ZfsNode(ExecuteNode): """determine uniq new snapshotname""" return self.backup_name + "-" + time.strftime("%Y%m%d%H%M%S") - def consistent_snapshot(self, datasets, snapshot_name, min_changed_bytes): + def consistent_snapshot(self, datasets, snapshot_name, min_changed_bytes, pre_snapshot_cmd=[], post_snapshot_cmd=[]): """create a consistent (atomic) snapshot of specified datasets, per pool. """ @@ -191,14 +192,24 @@ class ZfsNode(ExecuteNode): self.verbose("No changes anywhere: not creating snapshots.") return - # create consistent snapshot per pool - for (pool_name, snapshots) in pools.items(): - cmd = ["zfs", "snapshot"] + try: + for cmd in pre_snapshot_cmd: + self.verbose("Running pre-snapshot-cmd") + self.run(cmd=shlex.split(cmd), readonly=False) - cmd.extend(map(lambda snapshot_: str(snapshot_), snapshots)) + # create consistent snapshot per pool + for (pool_name, snapshots) in pools.items(): + cmd = ["zfs", "snapshot"] - self.verbose("Creating snapshots {} in pool {}".format(snapshot_name, pool_name)) - self.run(cmd, readonly=False) + cmd.extend(map(lambda snapshot_: str(snapshot_), snapshots)) + + self.verbose("Creating snapshots {} in pool {}".format(snapshot_name, pool_name)) + self.run(cmd, readonly=False) + + finally: + for cmd in post_snapshot_cmd: + self.verbose("Running post-snapshot-cmd") + self.run(cmd=shlex.split(cmd), readonly=False, valid_exitcodes=[]) def selected_datasets(self, exclude_received, exclude_paths): """determine filesystems that should be backed up by looking at the special autobackup-property, systemwide