Using Rsync and ZFS snapshots...

zfs-geek-backup can do incremental backups to removable drives, each backup drive is a full image plus snapshots.

My setup

• Hard drive dock
• Assortment of hard drives, new or used
• NAS4Free

Instructions

I have a basic NAS4Free system with one ZFS pool

pool:	My320POOL
state:	ONLINE
scan:	scrub repaired 0 in 1h12m with 0 errors on Fri Mar  1 12:09:30 2013
config:
My320POOL		ONLINE		0	0	0
mirror-0		ONLINE		0	0	0
ada1			ONLINE		0	0	0
ada0			ONLINE		0	0	0
errors: No known data errors

I have created several datasets

NAME					  USED	   AVAIL	REFER	MOUNTPOINT
My320POOL				  184G		110G	44.5K	/mnt/My320POOL
My320POOL/data			 1.48G		110G	1.47G	/mnt/My320POOL/data
My320POOL/install		 11.1G		110G	11.1G	/mnt/My320POOL/install
My320POOL/music			 7.62G		110G	7.62G	/mnt/My320POOL/music
My320POOL/photo			 14.5G		110G	14.5G	/mnt/My320POOL/photo
My320POOL/video			149.0G		110G	 149G	/mnt/My320POOL/video

To use zfs-geek-backup with a similar setup follow these steps

1. Attach the external drive and create a pool named zfsgeekbackup
2. Copy zfs-geek-backup.sh and open it for editing.
3. Edit the pool and dataset variables SOURCEPOOL=My320POOL and DATASETS=('data' 'photo')
4. Save and execute the script

You may run the backup at anytime

./zfs-geek-backup.sh //not so quiet
./zfs-geek-backup.sh -q  //quiet, only errors will output
./zfs-geek-backup.sh --dry-run  //adds --dry-run to the rsync commandline

Overview - What happens?

• You plug in one of the backup drives and your system sees it as a device but ZFS ignores it. You, or cron, run the backup script.
• It imports the zfsgeekbackup pool
• It creates a temporary dataset named TEMPzfsGEEKbackup
• It makes temporary snapshots of your selected datasets eg: DATASETS=('data' 'photo')
• It makes a temporary clone under TEMPzfsGEEKbackup of each snapshot eg: TEMPzfsGEEKbackup/photo
• It Rsyncs the incremental changes from TEMPzfsGEEKbackup to zfsgeekbackup
• It destroys the clones that it created
• It destroys the TEMPzfsGEEKbackup dataset that it created
• It destroys the temporary snapshots that it created
• It creates a snapshot on zfsgeekbackup eg: zfsgeekbackup@2013-03-05_01h52m48s
• It exports the zfsgeekbackup pool

You may now swap the backup drive and take it off site.

Tips

See what you have on a backup drive

zpool import zfsgeekbackup
zfs list -H -o name -t snapshot | grep zfsgeekbackup
ls /mnt/zfsgeekbackup/.zfs/snapshot
zpool export zfsgeekbackup

Get rid of all snapshots on zfsgeekbackup

zpool import zfsgeekbackup
zfs list -H -o name -t snapshot | grep zfsgeekbackup | xargs -n1 zfs destroy
zpool export zfsgeekbackup

Get a clean start on an existing zfsgeekbackup drive

zpool import zfsgeekbackup
zpool destroy zfsgeekbackup
zpool create zfsgeekbackup da1
zpool export zfsgeekbackup

Add another drive to your collection of backup drives

zpool create zfsgeekbackup da1
zpool export zfsgeekbackup

It's da1 on my machine but will likely be something different on yours

Immediately after you insert a drive into the dock your system should see it and spit out some messages like these below. Using the dmesg | tail command I can see that my drive is at da1. So... zpool create zfsgeekbackup da1 be careful now.

	nas4free# dmesg | tail
	da1 at umass-sim1 bus 1 scbus9 target 0 lun 0
	da1: WDC WD50 03ABYX-01WERA0 Fixed Direct Access SCSI-2 device
	da1: 40.000MB/s transfers
	da1: 476940MB (976773168 512 byte sectors: 255H 63S/T 60801C)
	nas4free#_