ZFS pool question

[Assign]

Hi,

Our PBS server needs some storage expansion. We would like to move to bigger disks now, to eventualy be able to add more in the future.

I would like to expand my Raidz3 pool Tank. I've ordered 6 new 22TB spinning disks. Goal would be to replace the existing 12TB drives. for moving the data we can add the drives to the enclosure as I still have 6 bays free.


Is there a way to:
- keep the name Tank
- keep the special device intact for this pool
- how about down time?

other question: would i be able to expand this in the future to 12 disks in raidz2 or Raidz3?

Thank you!

 

[s.lendl]

Hi

You can replace individual disks in your Tank pool one by one by using zpool replace <pool> <old> <new> [1]

• Replacing many disks in a large pool is time-consuming due to resilvering the data onto the new disks. In addition, you might consider running the zpool scrub command between disk replacements to ensure that the replacement devices are operational and that the data is written correctly.

After you finished replacing the disk, you will still set the old size with zpool get size.
You can expand the pool, to use the full size of the disks with:

zpool set autoexpand=on <pool>
zpool online -e tank <devices>

OpenZFS recently merged the RAID-Z-expansion feature into master [2] but has not been released. You will be able to use it once it's released in PVE. Please make sure to read the relevant documentation and discussion [3] regarding this feature.

Furthermore, since you are using 12TB and 22TB disks, I would like to point out, that this may be SMR disks. SMR disks are known to perform poorly with ZFS [4]. Make sure to verify beforehand, because shrinking a pool is not possible.

[1] https://docs.oracle.com/cd/E19253-01/819-5461/gazgd/index.html
[2] https://github.com/openzfs/zfs/pull/15022
[3] https://github.com/openzfs/zfs/discussions/15232
[4] https://truenas.com/community/threads/update-wd-red-smr-drive-compatibility-with-zfs.88413/

 

[Assign]

Thank you for your response.
I have Seagate Ironwolf Pro 22 TB drivers which are CMR:
https://www.techradar.com/news/seag...(ST22000NT001) has,SMR to reach that capacity.

I was hoping on a 'faster' copy strategy, without putting the redundancy down to z1. This will have to do then.