[comp.unix.ultrix] panic: rename: lost dir entry

zemon@felix.UUCP (10/03/87)

References:

Our Ultrix v2.0 crashed today with this panic.  I mention it
because it was caused (as far as I can tell) by an ordinary
user and it left file system damage which fsck did not
correct.

I was able to crash the system when logged in as myself (not
root) by executing the following two commands:

    % mkdir /sys/BINARY.vax/normal
    % mv /sys/BINARY.vax/normal /sys/BINARY.vax/normal.lat

I never got a prompt back from the "mv" command.  When the
system came back up, I found that both normal and normal.lat
directories existed and were hard linked.

    % ls -ldi /sys/BINARY.vax/normal*
    98697 drwxrwxr-x  3 zemon  512 Oct  2 10:48 /sys/BINARY.vax/normal
    98697 drwxrwxr-x  3 zemon  512 Oct  2 10:48 /sys/BINARY.vax/normal.lat

If you get a similar crash, you may want to go looking for
places where your heirarchical file system has become a
network.

	-- Art Zemon
	   By Computer:	    ...!hplabs!felix!zemon
	   By Air:	    Archer N33565
	   By Golly:	    moderator of comp.unix.ultrix

howie@cunixc.columbia.edu (Howie Kaye) (10/06/87)

We had a similar crash at Columbia, under Ultrix 2.0 on an 8700.
Since it only happened once, we didn't think much of it.  Anyway, to
get rid of the duplicate directory entries, i had to:

1) move all of the files in them somewhere else.
2) write a quick program to unlink one of them.   The directory has an
	extra link, so rmdir won't remove it, and it is a directory,
	so rm won't touch it... The program was just a single call to
	unlink.
3) rmdir the second directory.
4) rename things back to the way they should have been.

We were not running nfs at the time, so it coundn't have been caused
by our file system becoming a network.

------------------------------------------------------------
Howie Kaye				howie@columbia.edu
Columbia University 			hlkcu@cuvma.bitnet
Systems Group				...!rutgers!columbia!howie