Advice on Upgrading/Migrating an Old Possibly Failing Pool

Hello friends,

I need advice on whether I can upgrade a pool in place or I should take the extra effort to create a new pool and migrate the data.

I have an old 3 x 8TB raidz1 pool. I started to get some “permanent errors” and the list appears to be growing. There are no READ, WRITE, or CKSUM errors on the drives. I do have everything backed up via ZFS send/recv, but I’m a little nervous about the state of the backups because they have been updated after I started to get the “permanent errors”. Running a scrub did not repair anything and did not remove the permanent errors.

Should I avoid upgrading the pool in place with new drives?
Should I consider my backup compromised?

I can create a new pool and migrate the data but that will require me to shuffle some disks around and would be a real pain.

Any advice would be greatly appreciated.


I was able to get my permanent errors to go away by following the suggestion in this serverfault post. They suggested to start a scrub and then stop it to make the errors go away. I know this makes no sense but it worked for me.

do not run disks over 1tb in raidz1 configuration

Is this primarily because resilvering takes so long, or are there other reasons to not do raidz1 with big drives?

What do you mean by permanent errors?

Here is an example of the output that displays the “permanent error” (not my actual output because the errors are now gone for me)

pool: zstorage
state: ONLINE
status: One or more devices has experienced an error resulting in data corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
    entire pool from backup.
scan :scrub repaired 0B in 01:30:51 with 0 errors on Sun Apr  9 01:54:57 2023

    NAME                                          STATE     READ WRITE CKSUM
    zstorage                                      ONLINE       0     0     0
    raidz1-0                                      ONLINE       0     0     0
        ata-WDC_WD30EZRX-00DC0B0_WD-WCC1T1735698  ONLINE         0     0     0
        ata-WDC_WD30EZRX-00DC0B0_WD-WMC1T0506289  ONLINE         0     0     0
        ata-WDC_WD30EZRX-00MMMB0_WD-WCAWZ2711600  ONLINE       0     0     0

errors: Permanent errors have been detected in the following files:


What do you mean by upgrading the pool?

Sorry, I should have been more specific. By upgrading I mean that I intend to replace all my 8TB disks with 12TB disks.