Subject: Re: LFS fsck -- not clean?
To: Sverre Froyen <sverre@viewmark.com>
From: Konrad Schroder <perseant@hhhh.org>
List: current-users
Date: 09/19/2006 09:14:04
On Tue, 19 Sep 2006, Sverre Froyen wrote:
> While I am on the topic of LFS, I have noticed that fsck on a cleanly
> shutdown LFS file system usually shows some type of error or
> inconsistency. Is this to be expected or does it indicate some other
> problem.
This type of inconsistency is not expected, though I don't think it will
cause you a future panic either.
I've been working over the summer on getting the checkpoints solidly
consistent, using a test script that prevents the filesystem from wrapping
the log, and examines each checkpoint in turn for validity (using fsck_lfs
-n). This seems to be working now. Recently I've added "fsck_lfs -p" to
this test, rolling forward from every non-checkpoint partial-segment
write; there are some cases in which "fsck_lfs -p" still gets it wrong,
the cause of which I have yet to investigate.
I should point out, though, that if the checkpoints are indeed valid,
fsck_lfs -p will never give a more consistent filesystem, only a slightly
more recent view of the filesystem.
I haven't been explicitly testing shutdown/reboot, of course, nor even
umount, since the checkpoint should be the same no matter where it comes
from.
Take care,
Konrad Schroder
perseant@hhhh.org