removing a mirror (2xsmall drives) from FreeNas 11.3

[alexmc]

Hello Experts,

I have a FreeNAS 11.3 machine with six disks in one pool, 2 big, 2 medium, and 2 small. I want to simply remove the 2 small ones.
These are set up as three mirrors (vdevs?). The small disks are just wasting space and electricity. There is enough freespace on the machine to do without them.

A post here from 7 years ago says that I cannot make the pool smaller. I have a reasonable idea of how to replace disks with ones of equivalent size but that is not what I want.

I see that with ZFS I can do a zpool remove of a mirror eg

zpool remove poolname mirrorname

( https://docs.oracle.com/cd/E37838_01/html/E61017/remove-devices.html )

...being careful to get the mirrorname right. This tells the system that the pair of disks are in the REMOVING state and presumably data is copied off them onto other disks. I should be able to use zpool status poolname to see if the disks are ready to be disconnected entirely.

However that is not FreeNAS documentation and I can't see whether that is possible in the Web UI.

Does anyone know if this works fine in FreeNAS?

I am happy to upgrade to TrueNAS if that will help.

Thanks

 

[sretalla]

I think what you want is zpool detach poolname deviceidentifier

Managing ZFS Storage Pools - ZFS Administration Guide

illumos.org

Section 4.4.2

But actually what you are suggesting there is a feature I think was not present in the ZFS version of 11.3 (I could be wrong), which is removing an entire top level device from the pool.

Once you detach one of the devices, you may be able to remove the remaining single disk.

This is something that was added to the GUI in TrueNAS 12.0 CORE, so you'll have to work at the CLI if you're not going to upgrade.