ZFS Tools

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

Setup

Install the gem.

rake install

Setup crontab entries for scripts wanted. See below.

Scripts

zfs-auto-snapshot

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.

Usage

/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.

Crontab

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

Dataset setup

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

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

Overrides

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

zfs-snapshot-mysql

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.

Example MySQL+ZFS Setup

Datasets

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

ZFS Settings

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

MySQL Settings

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

Script Usage

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.

Crontab

*/10 * * * * /usr/local/bin/zfs-snapshot-mysql DATASET

DATASET - The dataset that contains your mysql data

zfs-cleanup-snapshots

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

Usage

Crontab

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