I've finally upgraded my troublesome oi-148a home storage box to oi-151a about
a week ago (using pkg update method from the wiki page - i'm not certain if
that repository is fixed at release version or is a sliding "current" one).
After the OS upgrade i scrubbed my main pool - 6disk raidz2 - and some checksum
errors were discovered on individual disks, with one non-correctable error on
the raid level. It named a file which was indeed not readable (io errors) so i
deleted it. The dataset pool/media has no snapshots, and dedup was disabled on
it, so i hoped the error is gone.
I cleared the errors (this only zeroed the counters, but still complained that
there were some metadata errors in pool/media:0x4) and reran the scrub. While
the scrub was running, zpool status reported this error and metadata:0x0. The
computer got hung and reset during the scrub, but apparently resumed from the
same spot. When the operation completed, however, it had zero checksum errors
at both disk and raid levels, the pool/media error was gone, but metadata:0x0
error is still in place.
Searching the list archive i found a similar post relevant to snv134 and 135,
and at that time Victor Latushkin suggested that the pool must be recreated. I
have some unique data on the pool, so i'm reluctant to recreate it (besides,
it's problematic to back up 10tb of data at home, and it can take weeks to try
and upload it to my work - even if there were so much free space there, which
So far i cleared the errors and started a new scrub. I kinda hope that if the
box won't hang, it might discover that there are no actual errors indeed. I'll
see that in about 100 hours. The pool is now imported and automounted, and i
didn't yet try to export and reimport it.
Still, i'd like to estimate now what are my chances of living on without
recreating the pool nor losing data? Perhaps, some ways to actually check, fix
or forge the needed metadata? Also, previously a zdb walk found some
inconsistencies (allocated !- referred); can that be better diagnosed or
repaired? Can this discrepancy by a few sectors worth of size be a cause or be
caused by that reported metadata error?
// Jim Klimov
sent from a mobile, pardon any typos ,)
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