Remove data VDEV from pool?

I dropped a clanger.

I installed some new disks into my server and added mirrored VDEVS into my pool (2 x 8TB drives).

I wanted to actually remove two 2 x 3TB VDEVS from the pool as the drives are old.

With me so far?

So, can I remove the mirrored VDEVS from the pool and “retire” the old drives?


Once you add an additional VDEV to the existing pool, I believe you can’t remove it.

Depends. What’s the layout of the rest of the pool? If all vdevs are either mirrors or single disks, then yes, you can remove one or more mirrored vdevs as long as there’s enough room on the remaining vdevs for the data.


Ah… very hack-ish & dangerous!.

No, that link is outdated.

VDev removal was added to OpenZFS


Not in the least–it’s a fully-supported feature of ZFS that’s been in the TrueNAS GUI since at least TrueNAS 12.


@dan & @Stux - Thanks!
learned something new.

That’s generally true for RAIDZ.

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