Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 21 Nov 1999 22:36:32 +1000
From:      Stephen McKay <syssgm@detir.qld.gov.au>
To:        freebsd-current@freebsd.org
Cc:        syssgm@detir.qld.gov.au
Subject:   Fsck follies
Message-ID:  <199911211236.WAA27489@nymph.detir.qld.gov.au>

next in thread | raw e-mail | index | archive | help
I was giving vinum + softupdates a bit of a workout on 4 really old
SCSI disks (Sun shoeboxes, if you must know) attached to an aha1542B.
The rest of the machine is a Pentium 133 with 64MB of parity ram, a
few more disks, and another aha1542B.  It runs -current (about 10 days
old now).

I was copying a newer -current source tree onto the box when I lost power
to my house for maybe half a second.  Being foolish and shortsighted, I
have no UPS.  (An interesting side note: out of the 3 machines in use at
the time, 2 of the keyboards locked up and required a power down to recover.
I was unaware that keyboards could crash.)

When the system came back up, fsck -p didn't like the vinum volume.
No sweat, I ran it manually.  There were many

    INCORRECT BLOCK COUNT I=<n> (4 should be 0)

messages.  I assumed this was an artifact of soft updates.  The fsck
completed successfully.

Being paranoid, I reran fsck.  This time it reported a number of
unreferenced inodes (199 to be exact), and linked them in to lost+found.

It is this last item that bothers me.  When the first fsck completed,
the filesystem should have been structurally correct.  But it wasn't.
A third fsck confirmed that 2 runs of fsck were enough.

I seem to recall sagely advice from days gone by to always run fsck twice
and sync thrice.  I thought I could forget all that stuff nowadays.

By the way, I saved the broken old source tree and compared it to the
full tree.  There were no unusual differences, except for the broken
one being incomplete.  So, if fsck were a little better, things would
be fine.  As good as you could expect, given a power failure.

Stephen.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199911211236.WAA27489>