Migrating pool from mirroring (RAID1) to RAIDZ1?

[OreoCookie]

I currently have two 8 TB Segate Ironwolf drives in a ZFS mirror, and have purchased another 8 TB Segate drive. Now I would like to create a RAIDZ1 with these three drives to increase the total amount of storage. Is that possible without offloading the data or will I need to destroy my mirrored storage pool and recreate one from scratch? Can I add drives to a RAIDZ pool afterwards to increase storage?

 

[Chris Moore]

Is that possible without offloading the data

No.

will I need to destroy my mirrored storage pool and recreate one from scratch?

Yes

Can I add drives to a RAIDZ pool afterwards to increase storage?

No.

There is a possibility that these current facts may change in the future, but this is the way it is today. Here is some material that may assist in your understanding:

Slideshow explaining VDev, zpool, ZIL and L2ARC
https://forums.freenas.org/index.ph...ning-vdev-zpool-zil-and-l2arc-for-noobs.7775/

 

[OreoCookie]

Thanks, that's what I thought, but I wanted to double-check. :)

 

[danb35]

There is a possibility that these current facts may change in the future, but this is the way it is today.

Specifically, there's work in progress to allow adding disks to a RAIDZn vdev (ETA this year, IIRC). Changing RAIDZ levels (e.g., RAIDZ1 to RAIDZ2) is not part of that project. I haven't heard anything about plans to allow changing a pool from mirrors (or a single disk, which could be easily created from a mirrored pool) to RAIDZn.

 

[Chris Moore]

Thanks, that's what I thought, but I wanted to double-check. :)

If you want, you could add a second mirror to the existing pool to extend capacity right now without needing to rebuild.

 

[OreoCookie]

If you want, you could add a second mirror to the existing pool to extend capacity right now without needing to rebuild.

If I understand correctly, then I would have the capacity of a single drive but a fault tolerance of two drives, correct?