ZFS Tools

Various scripts for administrating ZFS. Modeled after time-sliderd and ZFS Automatic Snapshots from OpenSolaris

Install the gem.

gem install zfstools

rake install

Setup crontab entries for scripts wanted. See below.

This will handle automatically snapshotting datasets similar to time-sliderd from OpenSolaris. Setup allows you to define your own intervals, snapshot names, and how many to keep for each interval. Zero-sized snapshots will automatically be cleaned up.

/usr/local/bin/zfs-auto-snapshot INTERVAL KEEP

• INTERVAL - The interval for the snapshot. This is something such as frequent, hourly, daily, weekly, monthly, etc.
• KEEP - How many to keep for this INTERVAL. Older ones will be destroyed.

15,30,45 * * * * root /usr/local/bin/zfs-auto-snapshot frequent  4
0        * * * * root /usr/local/bin/zfs-auto-snapshot hourly   24
7        0 * * * root /usr/local/bin/zfs-auto-snapshot daily     7
14       0 * * 7 root /usr/local/bin/zfs-auto-snapshot weekly    4
28       0 1 * * root /usr/local/bin/zfs-auto-snapshot monthly  12

Only datasets with the com.sun:auto-snapshot property set to true will be snapshotted.

zfs set com.sun:auto-snapshot=true DATASET

Setting a MySQL dataset's property to mysql will hook it into the zfs-snapshot-mysql script. See its section for setup instructions.

zfs set com.sun:auto-snapshot=mysql DATASET

Setting a PostgreSQL dataset's property to postgresql will cause zfs-auto-snapshot to put postgresql in online backup mode for the snapshot.

zfs set com.sun:auto-snapshot=postgresql DATASET

The user executing zfs-auto-snapshot will require passwordless login to the postgres database and will require either REPLICATION or SUPERUSER privileges. The easiest approach is to set up a trust or ident record in your pg_hba.conf. The zfs-auto-snapshot script will execute pg_start_backup() prior to saving the snapshot and execute pg_stop_backup() afterwards.

You can override a child dataset to use, or not use auto snapshotting by settings its flag with the given interval.

zfs set com.sun:auto-snapshot:weekly=false DATASET

Snapshots a mysql server's databases. This requires that mysql's datadir/innodb_data_home_dir/innodb_log_group_home_dir be a ZFS dataset.

tank/db/mysql
tank/db/mysql/bin-log
tank/db/mysql/data
tank/db/mysql/innodb
tank/db/mysql/innodb/data
tank/db/mysql/innodb/log

These settings should be set before importing any data.

zfs set primarycache=metadata tank/db/mysql/innodb
zfs set recordsize=16K tank/db/mysql/innodb/data
zfs set recordsize=8K tank/db/mysql/data
zfs set compression=lzjb tank/db/mysql/data

innodb_data_home_dir = /tank/db/mysql/innodb/data
innodb_log_group_home_dir = /tank/db/mysql/innodb/log
datadir = /tank/db/mysql/data
log-bin = /tank/db/mysql/bin-log/mysql-bin

Setup a /root/.my.cnf with the relevant information on where to connect to, with the proper username/password that has access to FLUSH LOGS and FLUSH TABLES WITH READ LOCK. The zfs-auto-snapshot script will automatically flush the tables before saving the snapshots.

Cleans up zero-sized snapshots. This ignores snapshots created by zfs-auto-snapshot as it handles zero-sized in its own special way.

*/20 * * * * /usr/local/bin/zfs-cleanup-snapshots