[wplug] crashh! ext2, fsck, and duplicate blocks

[Brandon Kuczenski]

On Sun, 31 Oct 2004, Carl Benedict wrote:

> > I am running a FreeBSD server (okay, okay, should I send it to wplug-bsd?
> > I think these questions are of general interest, though) and I had a
> > peculiar problem.  A configuration file for one of my scripts got
> > suddenly and unexpectedly filled with garbage.  The garbage looked like
> > this:
> >
>
> What did this script do?  Was it setup as a cron job or something else?
> Shell/perl/other?
>

It was a shell script to slowly (one directory at a time) copy files from
a remote host to the server using rsync, with the intent of keeping two
directory trees synchronized.  Sort of a poor-man's software RAID. (or a
lazy man's...)  But the script was disabled at the time of the crash.

> Did the system ever go down unexpectedly?  In my experience, it is not
> at all unusual to have some truncated or garbage disk entries after a
> crash.  This is especially true when you are using I/O intensive
> applications (like a database).  It sounds like you might have had a
> cross-linked file here.  This can somewhat of a hard thing to narrow
> down, especially if it happened a while back and you were not aware of
> any problems.  Had you disabled fsck for this volume for some reason?
> It sounds as if you had to invoke a manual fsck.

Yes, I did.. <see wmoran's post> ext2 is not natively supported on
FreeBSD.  Given this recent development, and your suggestion Bill, I think
I will get rid of the ext2 filesystems and format them both as ufs.

> A little OT: but this line:
>
> Oct 31 17:03:37 ocean /kernel: IP Filter: v3.4.31 initialized.  Default
> = pass all, Logging = enabled
>
> Default = pass all.
>

Yeah, I am filtering packets.  The first thing ipf does when it starts is
read a configuration file with "the rules."  And, unlike iptables, the
way ipf works is "the last matching rule sticks" rather than "the first
matching rule sticks."

Thanks for asking, though.  And thanks for your advice, bill -- in lieu of
a direct reply to your post -- I will take it.

-Brandon