Directory Storage on ZFS

[user8923428934]

Hi

Is it a good idea to create a ZFS pool from SSDs and then create a Directory on that pool into which you but the VMs (qcow2). I am asking because the normal ZFS setup (which we have been using for a while already and works great) does not have full snapshot capability (reverting to a older snapshot doesn't work without deleting the previous ones https://forum.proxmox.com/threads/rollback-to-some-nested-snapshot-zfs.63504/ which we need because of how we set up our DEV Lab)
Does this have any negative impact on performance? The other option I am seeing would be to use a hardware raid controller and LVM-thin but I would prefer ZFS if possible.

Thanks

 

[Dunuin]

Hi

Is it a good idea to create a ZFS pool from SSDs and then create a Directory on that pool into which you but the VMs (qcow2).
I am asking because the normal ZFS setup (which we have been using for a while already and works great) does not have full snapshot capability (reverting to a older snapshot doesn't work without deleting the previous ones https://forum.proxmox.com/threads/rollback-to-some-nested-snapshot-zfs.63504/ which we need because of how we set up our DEV Lab)
Does this have any negative impact on performance? The other option I am seeing would be to use a hardware raid controller and LVM-thin but I would prefer ZFS if possible.

In my opinion not because of the additional overhead of nested filesystems...specially when using copy-on-write of qcow2 on top of copy-on-write of ZFS. I would only do that if you really need it because of the qcow2 features (liek the one with the snapshot you already pointed out).

In case you don't need super fast snapshots/rollbacks then PBS might be a good alternative to snapshots for versioning, as you can save as much backups as you like without consuming additional space, as long as the guests data hasn't changed that much, because of deduplication. And you could easily clone guests from backups.

But you could do some tests yourself. Benchmark it with fio and have a look at the amount of data written with smartctl, and see if the performance drop and SSD wear increase is fine for you.

 

[LnxBil]

Does this have any negative impact on performance?

Just to be clear: Yes (and that is what @Dunuin described).

I also run such a setup exactly for the tree-like snapshot stuff.

 

[user8923428934]

Thanks for the answer. How big of a performance impact can I expect? 20% 50% in terms of IOPS and Read write speeds

 

[user8923428934]

Has anyone experience with the above mentioned PBS Backup restore features. I suppose if you would host the proxmox backup server on the same host as a VM and passthrough a few fast SSDs, that the Backup/Restore speeds should be usable right?