Hi
I have an up and running OPNSENSE system with the latest updates with 2 x 240GB SSDS running in software GEOM raid 1
Is it possible to add a 3rd 240GB SSD to add as a hot spare that would kick in if one of the disks in the raid 1 was to fail?
Or do i have to do this at installation?
Thanking you
J
A GEOM mirror? Really? Quite unusual. You are sure it's not ZFS? Please post the output of
gpart show
gmirror status
Hi Patrick
Thank you for your response.
I can confirm it is ZFS as I am able to take snapshots.
gpart show
=> 40 500118112 ada0 GPT (238G)
40 532480 1 efi (260M)
532520 1024 2 freebsd-boot (512K)
533544 984 - free - (492K)
534528 16777216 3 freebsd-swap (8.0G)
17311744 482805760 4 freebsd-zfs (230G)
500117504 648 - free - (324K)
=> 40 500118112 ada1 GPT (238G)
40 532480 1 efi (260M)
532520 1024 2 freebsd-boot (512K)
533544 984 - free - (492K)
534528 16777216 3 freebsd-swap (8.0G)
17311744 482805760 4 freebsd-zfs (230G)
500117504 648 - free - (324K)
gmirror status produces no output
I have created a os-monit service called raid_check path is /sbin/gmirror status tests is NonZeroStatus
This shows up in Monit status as
Program 'Raid_Check'
status OK
monitoring status Monitored
monitoring mode active
on reboot start
last exit value 0
last output -
data collected Mon, 15 Sep 2025 16:31:01
Hope all of this makes sense.
Cheers
J
Now the output of this command please - you are running a ZFS mirror, not a GEOM one:
zpool status
And yes, you can add a hot spare with ZFS.
With a mirror, a three-way mirror almost makes more sense than a hot spare. Hot spares are more useful for RAIDZ/RAIDZ2.