Cancellation of ZFS Expansion

TrueNAS General
1

I was in the process of runnings ZFS Expansion and one drive has error and been removed during the process; hence expansion has stopped.
I couldn’t quite see the best recommend procedure.
I’m using RAIDZ2 and unable to hot remove disks; therefore I’d need to power down to remove and install a new disk.

Is it possible to cancel the current expansion; so I can use that new disk as the replacement to do the resilver? Or can I safely set the failed disk as offline, power off, replace the disk; then power back on and resilver then continue the expansion?

Thanks…

2

Interesting. Truenas marked the disk online again, and the expansion is continuing…

# zpool status
  pool: Barracuda-Pool
 state: ONLINE
  scan: resilvered 664K in 00:00:10 with 0 errors on Mon May 26 08:58:23 2025
expand: expansion of raidz2-0 in progress since Sun May 25 09:50:07 2025
	13.2T / 31.9T copied at 165M/s, 41.51% done, 1 days 08:54:24 to go
config:

	NAME                                      STATE     READ WRITE CKSUM
	Barracuda-Pool                            ONLINE       0     0     0
	  raidz2-0                                ONLINE       0     0     0
	    sdg2                                  ONLINE       0     0     0
	    sda2                                  ONLINE       0     0     0
	    sdd2                                  ONLINE       0     0     0
	    sdi2                                  ONLINE       0     0     0
	    sde2                                  ONLINE       0     0     0
	    sdf2                                  ONLINE       0     0     0
	    3344c25d-3158-4f30-83ad-df4081c698e2  ONLINE       0     0     0
	    d534d530-d25e-4e8b-9885-533ba4708278  ONLINE       0     0     0
3

Just a sidenote – from your pool naming, I can assume that you are using seagate barracuda drives. Most of this line are SMR drives (check your model at the seagate site). And SMR drives are highly discouraged within ZFS.

2 Likes
4

Maybe they’re just trying to follow in TrueNAS’ footsteps of naming things after fish?

2 Likes
5

It is safe to power down while expanding or resilvering.

You cannot cancel the expansion process, and it will pause if a resilver needs to be performed.

And then once all the drives are back online (ie after you replace one etc), then it will continue.

2 Likes
6

Thanks for the feedback.
Yes the old pool was full of barracuda metal that I’m replacing gradually with CMR disks.