recommendations for zfs pool

[elterminatore]

hey,

i have about 20+ (unfortunately consumer) ssd's with 2TB left and a server with 24x 2,5 inch slots and i want to use that for a PBS.

now i am thinking about is the most sensible variant for a zfs pool. one big vdev with raidz2/3? multiple vdevs? special devices? what do you think?

regards
stefan

 

[Taylan]

You don't want to user consumer SSDs as any backup solution. With ZFS they'll get eaten very fast.
Ergo you answered your own question actually.

 

[elterminatore]

yes, I know that. There's a reason those SSDs are lying around and no longer used in the Ceph cluster. (Not because of the wearout, but because of the cache behavior and the performance under longer load). I just don't want to throw them away and also don't want to sell them. For "testing" it should be enough for now. In the longer term, these SSDs or the whole PBS will be replaced.
At the moment I only have a virtualized PBS with ISCSI storage on spinning disks. The performance is bad there. That's why I'm experimenting with the SSDs.

so let's just assume 20+ SSDs as the basis for the discussion.

 

[oversite]

yes, I know that. There's a reason those SSDs are lying around and no longer used in the Ceph cluster. (Not because of the wearout, but because of the cache behavior and the performance under longer load). I just don't want to throw them away and also don't want to sell them. For "testing" it should be enough for now. In the longer term, these SSDs or the whole PBS will be replaced.
At the moment I only have a virtualized PBS with ISCSI storage on spinning disks. The performance is bad there. That's why I'm experimenting with the SSDs.

so let's just assume 20+ SSDs as the basis for the discussion.

I am really a fan of mirrored vdevs ever since they could be removed. I would probably do 10 mirror vdevs. Else 2 vdevs with raidz2 or 3. A matter of taste.