Boot pool status is ONLINE: One or more devices has experienced an unrecoverable error.

[AJinNJ]

Saw a similar post, but I already have a pair of USB drives mirrored. How can I tell which one is "bad" so I can replace it? (I may replace both for sanity's sake, but I assume I should replace the "failed" device first?)

Code:

  pool: freenas-boot
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
        attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
        using 'zpool clear' or replace the device with 'zpool replace'.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-9P
  scan: resilvered 36.7M in 00:02:37 with 0 errors on Tue Sep 14 03:52:05 2021
config:

        NAME                                            STATE     READ WRITE CKSUM
        freenas-boot                                    ONLINE       0     0     0
          mirror-0                                      ONLINE       0     0     0
            da0p2                                       ONLINE      93   923   580
            gptid/46f7a5b7-1655-11e8-9fad-10bf48b6ddea  ONLINE       6     0     6

errors: No known data errors

Thanks!

 

[sretalla]

Have a look at dmesg | grep da0 and see if that gives you any clues... you may need to know which USB ports your motherboard considers as which number (and maybe account for 0-5 instead of 1-6, for example) and which controller accounts for which ports (front/back/other).

 

[AJinNJ]

OK, thanks for that. Are we (you) saying that da0 is the likely culprit of the errors, given the numbers of R/W/C errors in the zpool status output? I should "replace" that one in the pool first?

Thanks again.

 

[sretalla]

Are we (you) saying that da0 is the likely culprit of the errors, given the numbers of R/W/C errors in the zpool status output?

Yes.

Also, I would use it by process of elimination to find the other one since the gptid isn't available in dmesg output, but as it is, it's the one you're after.

If you have the option to add a new one and replace da0 before pulling it, sure, do that, which will allow you to just pull one or other of the existing ones to find the broken one after that.

You would/will still have to look at BIOS boot settings to make sure your next boot will be successful to the new and still good old sticks.

 

[AJinNJ]

Thanks for that (again). The GUI/web-interface doesn't seem to allow for adding a third disk for mirroring.

I could try zpool attach, but I have to supply an existing device...I suppose I should use the gptid device, because it has far fewer errors reported? Once that is resilvered, I and use zpool detach to remove the "failed" device so the mirror is back to 2 devices?