Introduction:
In this blog post we are going to create a Mirrored file system using ZFS.
We are going to use 5 Disks, 4 for data and 1 as a hot spare.
The disks will be 200GB with a combined size of 1TB, but acutal usable space will only be 400GB.
This file system has the ability to support 2 disks failing and to have one disk replaced automatically by ZFS its self.
Commands:
zpool create mypool mirror disk01 disk02 zpool addmypool mirror disk03 disk04 zpool add mypool spare drive05 zpool set autoreplace=on mypool
Check:
zpool list
NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT mypool 390M 120K 390M 0% 1.00x ONLINE -
zpool status
pool: mypool
state: ONLINE
scrub: none requested
config:
NAME STATE READ WRITE CKSUM
mypool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
/zdisk/disk1.img ONLINE 0 0 0
/zdisk/disk2.img ONLINE 0 0 0
mirror-1 ONLINE 0 0 0
/zdisk/disk3.img ONLINE 0 0 0
/zdisk/disk4.img ONLINE 0 0 0
spares
/zdisk/disk5.img AVAIL
errors: No known data errors
You can now access the new file system under “/mypool” and begin adding files there in the knowledge that should 1 disk fail, ZFS will auto replace it with the spare, giving you time to replace the drive.