Tip: If you host PVE on ZFS check for storage pool upgrades after a major version upgrade (Example: 8 to 9)

[jkotran]

Hey,

My PVE hosts use zfs. After upgrading from 8 to 9 I had to do the following to upgrade zfs on disk. I didn't notice this in the upgrade manual:

sudo zpool status

(Check that your storage is healthy.)

sudo zpool upgrade rpool

Be sure to do something like that for any other storage pools that you may have.

 

[Stoiko Ivanov]

I didn't notice this in the upgrade manual:

The reason why we don't add it there is that this is a one-way street - once you've upgraded your zpools you cannot use a kernel that is shipping an older (minor) version for ZFS.

In general I'd recommend to rather upgrade a zpool if you need one of the new features and have ensured that your hardware runs fine with the current kernel!

I hope this explains it.

 

[jkotran]

Hey Stoiko,

Thank you for the thoughtful reply and for sharing your insight.

I agree with you.

Cheers

 

[bgkprmx]

@jkotran chatting with ChatGPT about my zfs setup I noticed my server's ZFS pools are not upgraded. Is it safe to upgrade?

 

[UdoB]

chatting with ChatGPT about my zfs setup I noticed my server's ZFS pools are not upgraded. Is it safe to upgrade?

Why don't you ask that simulated intelligence?

You may read man zpool-upgrade.

After executing "zpool upgrade" and using (as far as I know) those features you need a kernel module with a new enough zfs kernel module to utilize ZFS.

In PVE context that works fine, all 9.x versions are compatible, as far as I know. That problem area is only relevant if one would try to use a PVE 8.x installation-.iso on a PVE 9.x installation - with that newer ZFS version.

On the other hand: if you do NOT use those features then there is no need to enable them ;-)

Edit: man zpool-features gives a short overview of the current ones.