add disk to zfs1 3 disk?

[openaspace]

Hellooooo
I'm wrong or I can't add(expand) a new disk of the same size to a zfs1 pool with 3 disk , single parity?

 

[Dunuin]

zfs1 pool with 3 disk , single parity

What do you exactly mean?
A 3 disk raidz1 you want to expand to a 4 disk raidz1?

As far as I know that feature isn't implemented yet, but should be added soon. Maybe we will get it with PVE 7.4.
So the usualy way would be to backup all stuff, destroy that pool and recreate it with one more disk.
When also booting from it, you would need to install PVE from scratch.

 

[openaspace]

Yes, expand the raid maintaining the single parity.

When will be released the 7.4?!?

I run pve on raid card ext4 with vm and only data is stored on the zfs pool

 

[Dunuin]

First it has to be released in OpenZFS. Then PVE needs to use the OpenZFS version that supports it, and I would guess this would only be added to a minor release to not break things. And we just got PVE 7.3 some days ago. So my bet would be that it will take some time.

Some articles on this:
https://arstechnica.com/gadgets/2021/06/raidz-expansion-code-lands-in-openzfs-master/
https://github.com/openzfs/zfs/pull/12225
https://louwrentius.com/zfs-raidz-expansion-is-awesome-but-has-a-small-caveat.html