Re: Reducing UFS corruption from unclean shutdowns?

From: Scott Long <scottl_at_samsco.org>
Date: Fri, 21 Jun 2019 14:27:09 -0600
> On Jun 21, 2019, at 2:09 PM, Alan Somers <asomers_at_freebsd.org> wrote:
> 
> On Fri, Jun 21, 2019 at 1:56 PM Scott Long <scottl_at_samsco.org> wrote:
>> 
>> 
>> 
>>> On Jun 21, 2019, at 1:49 PM, Alan Somers <asomers_at_freebsd.org> wrote:
>>> 
>>> I panic my development VM regularly.  Each time, I need to fsck the
>>> file system.  Even if I had run sync(8) just before the panic, I
>>> frequently find corruption.  What should I change to make sync(8)
>>> work, or at least to make corruption rare?  It looks like my root file
>>> system is using soft-updates+journal.  Should I disable those?
>>> 
>> 
>> What corruption do you regularly see?
>> 
>> Scott
> 
> fsck reports various types of errors, all repairable, like "INODE
> CHECK-HASH FAILED", "FREE BLK COUNT(S) WRONG IN SUPERBLK", "SUMMARY
> INFORMATION BAD", "BLK(S) MISSING IN BIT MAPS", and "UNREF FILE".  If
> I don't run fsck, then I get errors when I try to access files.  Like
> "inode XXX: check-hash failed" and "such and such is marked as an
> executable file but could not be run by the operating system".
> -Alan

The freeblk count and summary information messages are normal and expected.  I
don’t think that the blks missing message is expected, and the unref file message is
definitely a red flag of something that should have been handed with journal
recovery.  Kirk and Chuck, do you have any insight here?

Thanks,
Scott
Received on Fri Jun 21 2019 - 18:27:13 UTC

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