Re: ZFS: Rescue FAULTED Pool

On 01/02/2025 10:57, A FreeBSD User wrote:
> Hello, this exactly happens when trying to import the pool. Prior to the loss, device da1p1
> has been faulted with numbers in the colum/columns "corrupted data"/further not seen now.
> 
> 
>   ~# zpool import
>     pool: BUNKER00
>       id: XXXXXXXXXXXXXXXXXXXX
>    state: FAULTED
> status: The pool metadata is corrupted.
>   action: The pool cannot be imported due to damaged devices or data.
>          The pool may be active on another system, but can be imported using
>          the '-f' flag.
>     see:https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-72
>   config:
> 
>          BUNKER00    FAULTED  corrupted data
>            raidz1-0  ONLINE
>              da2p1   ONLINE
>              da3p1   ONLINE
>              da4p1   ONLINE
>              da7p1   ONLINE
>              da6p1   ONLINE
>              da1p1   ONLINE
>              da5p1   ONLINE
> 
> 
>   ~# zpool import -f BUNKER00
> cannot import 'BUNKER00': I/O error
>          Destroy and re-create the pool from
>          a backup source.
> 
> 
> ~# zpool import -F BUNKER00
> cannot import 'BUNKER00': one or more devices is currently unavailable


Too late now, but another useful command for situations like this is
zdb -G BUNKER00
It would print a log of various pool import actions.

E.g., on a good pool:
# zdb -G rpool

ZFS_DBGMSG(zdb) START:
spa.c:5694:spa_open_common(): spa_open_common: opening rpool
spa_misc.c:419:spa_load_note(): spa_load(rpool, config trusted): LOADING
vdev.c:162:vdev_dbgmsg(): disk vdev '/dev/gpt/S6PEN.rpool': best uberblock found 
for spa rpool. txg 61892397
spa_misc.c:419:spa_load_note(): spa_load(rpool, config untrusted): using 
uberblock with txg=61892397
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading checkpoint txg
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading indirect 
vdev metadata
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Checking feature flags
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading special 
MOS directories
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading properties
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading AUX vdevs
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading vdev metadata
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading dedup tables
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Loading BRT
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Verifying Log Devices
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Verifying pool data
spa_misc.c:419:spa_load_note(): spa_load(rpool, config trusted): spa_load_verify 
found 0 metadata errors and 4 data errors
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Calculating 
deflated space
spa_misc.c:2311:spa_import_progress_set_notes_impl(): 'rpool' Starting import
spa.c:8925:spa_async_request(): spa=rpool async request task=2048
spa_misc.c:419:spa_load_note(): spa_load(rpool, config trusted): LOADED
ZFS_DBGMSG(zdb) END

On a bad pool, the log may have helped to identify the exact problem.

-- 
Andriy Gapon