ZFS two isolated pools?

[mefizto]

Greetings all,

assuming creation of two pools:

zpool create m_pool mirror disk_01 disk_02
zpool create z2_pool raidz2 disk_03 disk_04 disk_05 disk_06

will the two pools be independent? The idea is to have fairly immutable files, i.e., movies, music on the z2_pool, and use the m_pool for often changing regular work files. Any disadvantages of this approach?

Thank you,

M

 

[usdmatt]

Yes they will be independent. Assuming the disks are all the same size these are the only [dis]advantages I can come up with:

Advantages:

Loss of an entire pool will only affect work or media files, not both.
If your work files will also fit on the RAID-Z2 pool, you could use zfs send/recv to store a second copy so loss of the entire mirror would be pretty easy to recover from. (depending on the importance of the files it may still be reasonable to back them up somewhere else as well)

Disadvantages:

You have slightly less redundancy for your work files - although you can alleviate that by storing a copy on the RAID-Z2 pool as mentioned above.
If your work files only take up a small amount of storage, you may make more effective use of space by combining into one 6 disk RAID-Z2 which would give you 4 x disk_size for all your data, instead of 1 x disk_size for work and 2 x disk_size for media.

 

[mefizto]

Hi @usdmatt,

Thank you for the reply. Both pools will, of course, be backed up to another server, I learned my lesson when, only by luck and a lot of effort, was I able to recover my data from a failed drive in the past. I understand the loss of space use efficiency, but I belong into the - space is cheap - camp, and restoring a work data on 500 GB drive is less time consuming than 4 TB raid_z2.

Kindest regards,

M