[net.unix-wizards] Why can't I mount or unmount /usr?

govern (12/03/82)

I have a VAX 11/780 with USG UNIX Ver. 4.2 (~~ 4.0).  Something is
corrupted that prevents me from mounting or unmounting the /dev/rp1
file system which contains /usr.  The files are all there, so it at
least ACTS mounted.  I have another  file system on /dev/rp4, which
I would like to mount on /usr/ipws, but can't. (It mounts fine on
/bck.)  In both cases I get "device busy" errors when I try to mount
or umount.  Changing /etc/mnttab hasn't helped, although maybe I've
missed  something?

			HELP!!

			Thanks;

			Bill Stewart  BTL-WB 201-870-7699 (After 2:30 Friday)
			houxn!hoscf!wcs, or
			 	ucbvax!ihnss!hoscf!wcs or decvax!harpo!hoscf!wcs

roediger.ANL-MCS@SRI-UNIX@sri-unix (12/15/82)

From: roediger.ANL-MCS at SRI-UNIX (Gary &)
Date: 10 Dec 1982 09:44:47-PST
The accounting file is probably being used.  Try turning the accounting off
first; then umount it.
					Gary Roediger
					ucbvax!anlams!roediger
					roediger@ANL-MCS

Michael.Young.CMU-CS-A@SRI-UNIX@sri-unix (12/15/82)

From: Michael Wayne Young <Michael.Young.CMU-CS-A@SRI-UNIX>
Date:  9 December 1982 1408-EST (Thursday)
Often mount/unmount is impossible because some process's current
directory is on that filesystem or some file is open there.  I know
of at least one kernel that "revokes" access to files on a structure
if you try to dismount it, but I don't think it tries to get rid
of processes whose current directory is on it (as that's harder
to decide what to do).  You might want to see if some process
that's always running that is stopping you up.

Does your flavour of Unix allow mounts on top of already mounted
systems?  [I'm unfamiliar with the USG-related ones.]  That might
be a no-no entirely.  Otherwise, I can't tell why you wouldn't
be able to handle mounting on /usr/foo.

			Michael