SOLVED V Low priority - removed 1 mirrored boot, trying to 'put back'

[Bikerchris]

Hello all,

Very Quick Summary:
- Removed 1 of 2 mirrored boot drives from TrueNAS-12.0-U2.1 Server temporarily (formatted)
- Used in other machine
- Wanted to put back in original TrueNAS
- Having difficulty with correct command.

Zpool status:

pool: freenas-boot
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: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
scan: scrub repaired 0B in 00:00:29 with 0 errors on Sat Apr 10 03:45:29 2021
config:

NAME STATE READ WRITE CKSUM
freenas-boot DEGRADED 0 0 0
mirror-0 DEGRADED 0 0 0
ada3p2 ONLINE 0 0 0
ada9p2 UNAVAIL 0 0 0 cannot open
errors: No known data errors

Drive info:

Name: ada9
Boot Mirror2
Mediasize: 250059350016 (233G)
Sectorsize: 512
Mode: r0w0e0
descr: HFS250G32TND-3112A
ident: FI5CN05921020CL1V
rotationrate: 0
fwsectors: 63
fwheads: 16

Very sorry to bother you, self-inflicted situation, but I'm still in the learning process, no live/priority data/config involved. I have researched and tried for an hour or so, but I'm afraid I just don't have the knowledge yet.

I have TrueNAS on a system with 2 mirrored SSD boot drives. I needed to 'borrow' one of the SSD's urgently to be installed in another machine. to help a friend out I had hoped that I would be able to remove it, use it in a separate machine, format it, put it back in the TrueNAS machine and resilver. I'm having difficulty with the latter at the moment and can't see a method - I have looked into to it, but I'm not clued up yet.

I have tried a number of commands to no avail. What I was hoping to do, was to make the disk online and let it resilver.

Thanks in advance for your help, and sorry again to bother you!

 

[sretalla]

So If I understand you right, you haven't removed the disk from the mirror in the first instance when you took it out?

In that case, you'll need to do that (zpool detach freenas-boot ada9p2)

Then you should wipe it in the GUI and attach it under system | boot | Actions | Boot Pool Status | ... then Attach

 

[Bikerchris]

@sretalla , you're a gentleman, thank you.

I've used your guidance, the config is restored, brilliant job and I still regret having to ask, but thank you again! The resilver took around 1 minute.
Just while on this subject, my motherboard has SATA and an NVMe ports - do you think it's worth me making 1 SATA SSD and 1 NVMe drive as mirrored boot drives on future installs? I thought it may be sensible to have two different types of media/connections for increasing reliability, but may be it can be troublesome? Very much welcome your thoughts if you have a moment.

 

[sretalla]

do you think it's worth me making 1 SATA SSD and 1 NVMe drive as mirrored boot drives on future installs?

Generally speaking a mirrored boot is not necessary for non-enterprise installs (and maybe not even for them).

A single SATA SSD is plenty for the demands placed on the boot pool. Mirroring only really makes a lot of sense if you're using USB sticks.

Just make sure you keep a config backup somewhere and you can always restore in around 15 minutes to a new SSD if it ever becomes necessary.

 

[Bikerchris]

Generally speaking a mirrored boot is not necessary for non-enterprise installs (and maybe not even for them).

A single SATA SSD is plenty for the demands placed on the boot pool. Mirroring only really makes a lot of sense if you're using USB sticks.

Just make sure you keep a config backup somewhere and you can always restore in around 15 minutes to a new SSD if it ever becomes necessary.

Thank you very much for shedding light, I'll re-evaluate, sounds like I've been a little excessive. The final server is intended for business use, though I'll be the only one using it most of the time.

When I do the final install, I'll do as you say and only use one SSD, I can leave the other one of a shelf and ensure I do regular config backups away from the machine. My intention is to have a snapshot server, so I can place them on that.

Your help has been genuinely and thoroughly appreciated.