ZFS Expand Pool from 3 to 4 - Wrong Pool State myzfs - invalid expansion. 6.12.0-rc6 Bug?

[montybathrhino]

I'm trying to expand my zfs pool named myzfs from 3 to 4. After adding a undefined drive of the same size to the 4th slot in the pool and hitting start I get: 

 

Wrong Pool State

myzfs - invalid expansion

 

Unraid version: Version: 6.12.0-rc6 

 

File system type for pool is: 

zfs, raidz,  1 group of 3 devices

 

Logs show:
May 31 12:15:34 sponge emhttpd: import 30 cache device: (sdb) VMware_Virtual_SATA_Hard_Drive_00000000000000000001
May 31 12:15:34 sponge emhttpd: import 31 cache device: (sdc) VMware_Virtual_SATA_Hard_Drive_02000000000000000001
May 31 12:15:34 sponge emhttpd: import 32 cache device: (sdd) VMware_Virtual_SATA_Hard_Drive_03000000000000000001
May 31 12:15:34 sponge emhttpd: import 33 cache device: (sdf) VMware_Virtual_SATA_Hard_Drive_05000000000000000001
May 31 12:15:34 sponge emhttpd: myzfs: invalid expansion: not multiple of 3
 

Device count in pool config is greyed out - not changable.

 

Am I missing something?  What is the procedure to expand ZFS from 3 > 4?

 

Thanks!
 

-Justin

 

[JorgeB]

You cannot add a single device to a raidz zfs pool,  you can add another vdev of the same width, in this case another 3 devices. 

[gabriel20xx]

Is it still not possible to expand a raidz zfs pool from 3 to 4 disks with all the same sizes?

[itimpi]

2 minutes ago, gabriel20xx said:

Is it still not possible to expand a raidz zfs pool from 3 to 4 disks with all the same sizes?

Not as far as I know.   I think this is a feature that has been 'promised' for some time but has not yet made into general release.

[amiskell]

It hasn't been merged into OpenZFS yet, it's still a pending item.

 

You can follow along on the status at https://github.com/openzfs/zfs/pull/15022, when it gets merged and into a release of OpenZFS it can be included into UnRAID.

 

Work on the feature had stalled for awhile but was picked back up in June with backing from iXSystems to sponsor the work to get it completed and merged into OpenZFS.