Subject: strange nfs problem
To: None <current-users@NetBSD.ORG>
From: Thorsten Frueauf <frueauf@ira.uka.de>
List: current-users
Date: 04/08/1997 20:28:15
Hello!

Since I got my Toshiba Tecra 500 CDT laptop, I have a strange problem with nfs:

I have three machines connected via ethernet:
	(cyberdyne) Amiga 3000 with CS 060 MK2, ariadne ethernet
	(cybersil)  HP 9000/400T with internal ethernet
	(cyberlap)  Toshiba Tecra 500 CDT with 3COM 3C589C Etherlink III

and I use the Amiga as backup machine via its local SCSI bus and a HP35470A
DAT drive connected. On the two other machines I export all local filesystems
via nfs to the Amiga:

/etc/exports on the HP 9000/400T:
/               -maproot=root   cyberdyne
/usr            -maproot=root   cyberdyne

/etc/exports on the Toshiba Tecra 500 CDT:
/               -maproot=root   cyberdyne
/usr            -maproot=root   -alldirs        cyberdyne cybersil

So I just mount the filesystem that I want to backup on the amiga to /mnt
and do a `tar --unlink -cvpf /dev/nst0 .` from /mnt.

This works very well, except that after I did:

on the amiga:
	cd /root
	mount cyberlap:/ /mnt
	cd /mnt
	tar --unlink -cvpf /dev/nst0 .
	cd /root
	umount /mnt
I get:
umount: /mnt: Device busy

and that with no shell being on /mnt or using anything of it. All other
filesystems have been able to umount after been backuped.

If I just do (on the amiga, fresh booted):
	cd /root
	mount cyberlap:/ /mnt
	cd /mnt
	cd /root
	umount /mnt

it works! Surprisingly I _don't_ have that problem with cyberlap:/usr ?!

This is absolutely reproducable and behaves alway this way :-(

Any ideas on what is causing that? I thought about endian problem (as I never
had problems mounting-backup-umounting / from the hp300), but then I should
have the same problem with mounting-backup-umounting /usr from the i386 machine?

Thanx for any help in advance!

Greets
      Thorsten

PS: All machines run NetBSD current of course, at the moment from the
    07.04.1997 sources, but this is since at least Dezember 1996, when I got
    my laptop.