fsck and dump freeze freebsd. any ideas?
Edward Sanford Sutton, III
mirror176 at cox.net
Wed Jul 29 08:36:54 UTC 2009
The smartctl tests on the three drives came back saying they were checked
100% without error; bad sectors have always caused an error and an aborted
scan at the point of trouble for me in the past.
I 'thought' I recalled seeing a panic along the lines of ffs_free or
something related to free blocks or something at one point; maybe that was an
error with fsck on the live system when manually ran. I will try to
reproduce. Otherwise I do not know that fsck crashes; the entire system
locks. I will see if I can reproduce the problem as a panic.
There were some errors fsck seems to think it cleaned. A couple still exist
indicating wrong counts about '12 should be 4' or '4 should be 0' type stuff.
One error had a ridiculously large seven digit or so number that fsck said
should be reduced. I had made a many terabyte file with a dd write to the end
of a file of the largest size it would let me create and have since deleted
the file; maybe that was what the reference was to. After fixing some errors,
the fsck still causes a freeze and at what seems to be about the same point.
The filesystem was unmounted for the dump and fsck has been attempted both
mounted and unmounted. The filesystem has (ufs, NFS exported, local,
soft-updates) reported for features by mount under normal operation.
The freeze with dump did occur during a snapshot creation, which I found I
cannot kill with a -9 (kill attempted minutes before the crash which still
would not stop the creation).
The powerdown question is more for how to handle an unsafe powerdown/crash
on an active system. If I need to read from a partition, would read only
leave it completely clean? Is there a way to operate on a file system which
is treated as more of a ramdisk of changes and keeps the real partition
unmodified (giving results like Faronics deepfreeze software or qemu disks in
Would a zfs mirror configuration handle the unexpected crash/powerdown?
Would it just report and fix the corruption, mention what files/structures
weror impacted, offer restore of that data from a recent snapshot, or just
say it is time to restore from a backup?
Thanks again for the feedback,
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