Pool unmountable even if zpool import report that it can

[Bidule0hm]

There is a member in the french section who has a problem to mount his pool (here), and who don't know enough english to post here. I've done everything I can to help him but it's not enough, I need some help to figure out what happens.

Long story short: after a power outage his pool doesn't mount anymore and he has a whole bunch of this errors:

Code:

(ada4:ahcich4:0:0:0): READ_FPDMA_QUEUED. ACB: 60 10 b0 92 69 40 18 00 00 00 00 00
(ada4:ahcich4:0:0:0): CAM status: ATA Status Error
(ada4:ahcich4:0:0:0): ATA status: 41 (DRDY ERR), error: 40 (UNC )
(ada4:ahcich4:0:0:0): RES: 41 40 b1 92 69 40 18 00 00 00 00

zpool import reports that everything is OK and that the pool can be imported:

Code:

[root@freenas] ~# zpool import
   pool: tank
     id: 18416255718950753427
  state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:

        tank                                            ONLINE
          raidz1-0                                      ONLINE
            gptid/f0766277-546d-11e4-9ad6-bcee7b870dd5  ONLINE
            gptid/f0bdb44b-546d-11e4-9ad6-bcee7b870dd5  ONLINE
            gptid/f1233fbe-546d-11e4-9ad6-bcee7b870dd5  ONLINE
            gptid/f1b1bbff-546d-11e4-9ad6-bcee7b870dd5  ONLINE
            gptid/f1fcc4dc-546d-11e4-9ad6-bcee7b870dd5  ONLINE

but when he tries to import it there is the following error:

Code:

root@freenas] ~# zpool import -R /mnt tank
cannot import 'tank': one or more devices is currently unavailable

ada2 report 8 unreadable sectors and ada4 1 unreadable sector after a long SMART test.

I've put the hardware and the output of the usual debug commands in this pastebin: http://pastebin.com/v4fJRbf9

Anyone have an idea?

 

[Bidule0hm]

Well, after a re-install of FreeNAS on a new USB stick and some further debugging I cam to the conclusion that ada2 and ada4 are too much trashed and prevent the pool from mounting.

He has some important and not backuped data on this pool so any "last hope" idea is welcome...