ZFS Expansion Help

[liamstears]

I am about to create a new ZFS mirror pool with two 2tb drives, in the future however I would like to expand this to three drives using raidz, how can I go from a mirrored pool with 2 drives to a 3 drive raidz?

 

[leesteken]

how can I go from a mirrored pool with 2 drives to a 3 drive raidz?

I think the only possibility is deleting the whole mirror and creating a new raidz. This is not Proxmox specific, so maybe ZFS experts and forums know better than me.

EDIT: If you care about your data, you'll have backups which you can then restore on the raidz (since you lose the data on the mirror when you delete it).

 

[news]

Right you build a new RaidZ1 Pool an copy then the Files with the ZFS Tool send .. | ZFS receive .. to the new Pool.
But if there are HDDs in you pool, you need a ZFS Special Device of the same class for the zfs meta data. And have the also other option, small files to store there also.

You can then add then add other partions for ZFS ZIL Logfile and/ or ZFS cache.

Last week i use 2x 4 TB Seagate IronWolf Pro 4TB HDDs with 2x 1 GB NVMe Pcie 4 x4 and add ZFS special device, ZFS ZIL Logfile and ZFS cache to my new pool.
The setup was tricky, because i use the 2x NVMe also as zfs mirror rpool device.

 

[Kingneutron]

Do you intend on using the raidz1 for storage or VMs? Storage will be fine but I/O for VMs will be too slow.

You can expand a mirror into a "RAID10 equivalent" by adding 2 more drives of equal (or larger) size, that is more ideal for VM usage.