Moving disk from a stripe into a mirror

[sitthirt]

I run a FreeNAS system on a HP mini server since 7 years any was glad having it. It always worked very fine, even with replacing small disks with bigger ones and replacing disks with bad SMART status to new ones.
During the last days one of my disks died completely without warning in advance, it does not spin anymore.
I tried to replace it like the runs before, but i could not get it done right, now it looks like this:
[root@freenas ~]# zpool status
pool: WD-RED-4TB_2x
state: DEGRADED
status: One or more devices could not be opened. Sufficient replicas exist for
the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
see: http://illumos.org/msg/ZFS-8000-2Q
scan: scrub in progress since Sat Dec 10 19:55:45 2022
1.06T scanned at 739M/s, 317G issued at 216M/s, 4.24T total
0 repaired, 7.31% done, 0 days 05:18:33 to go
config:

NAME STATE READ WRITE CKSUM
WD-RED-4TB_2x DEGRADED 0 0 0
mirror-0 DEGRADED 0 0 0
545426437007293103 UNAVAIL 0 0 0 was /dev/gptid/fc20c27a-9ae2-11e5-a06a-3ca82aa05
06c
gptid/fc910e9a-9ae2-11e5-a06a-3ca82aa0506c ONLINE 0 0 0
mirror-1 ONLINE 0 0 0
gptid/c64a4f9d-9809-11e8-b118-3ca82aa0506c ONLINE 0 0 0
gptid/7129e787-4a4f-11ed-9459-3ca82aa0506c ONLINE 0 0 0
gptid/985ead71-7804-11ed-a5fa-3ca82aa0506c ONLINE 0 0 0

errors: No known data errors

pool: freenas-boot
state: ONLINE
scan: scrub repaired 0 in 0 days 00:03:26 with 0 errors on Wed Dec 7 03:48:26 2022
config:

NAME STATE READ WRITE CKSUM
freenas-boot ONLINE 0 0 0
gptid/ceb4e7b0-aa29-11e5-8728-3ca82aa0506c ONLINE 0 0 0

errors: No known data errors
[root@freenas ~]#

As you see (I guess the bold marks are the important ones), my intention was to get the new drive (985ead71-7804-11ed-a5fa-3ca82aa0506c) into the mirror-0 as replacement for the 545426437007293103 failure. Anyway by own not-ability the new drive is now in a stripe instead mirror of the one OK disk in mirror-0.
It seems to me that there is no option in the GUI of FreeNAS 11.1-U7 to "move" the new disk into the mirror-0. That the scrub runs at the moment is just coincidence.
Has anyone a solution witout having to reload all my files on to 2 mirror-sets from backup by rebuilding the system from scratch again? I'm not afraid of command-line. I did not intentionally write anything on the NAS since the failure, so there should be no relevant data on the new drive.
Thank you very much in advance!

 

[sitthirt]

Maybe this shows my Problem better than the command-line. ada0 is the new disk, which should have replaced 54...03.

 

[danb35]

It seems to me that there is no option in the GUI of FreeNAS 11.1-U7 to "move" the new disk into the mirror-0.

That's correct; vdev removal (which is what you'd need in order to remove the striped disk from the pool) didn't land until 11.2 (IIRC) in the CLI, and 12.0 in the GUI. Since even 12.0 is EOL, you really should be giving serious thought to an upgrade. But in the short term, upgrading to 11.2 should allow you to do zpool remove WD-RED-4TB_2x gptid/985ead71-7804-11ed-a5fa-3ca82aa0506c. From there, you can attach the disk to mirror-0.

 

[sitthirt]

Thank you for your instant reply, danb35!
I plan to update next weekend.
Best Regards