From: =?iso-8859-1?Q?Peter_=C5strand?= Subject: Re: broken umount -f Date: Mon, 13 Jan 2003 10:44:33 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org Message-ID: References: <15905.56794.440587.792199@charged.uio.no> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: nfs@lists.sourceforge.net, Return-path: To: Trond Myklebust In-Reply-To: <15905.56794.440587.792199@charged.uio.no> List-ID: >>For as long as I remember, umount -f has been broken. I got a reminder >>of this fact today when we took an older NFS server out of use. I had to >>reboot almost all machines that had mounts from this server. Not nice. ... > AFAICS It works for me. > > Are you using the 'intr' mount option, Yes, as often I can. But IMHO, it should be possible to unmount an unreachable NFS fs even if it wasn't mounted with "intr". Otherwise we have a quite silly "sysadmin trap". >and are you remembering to kill > those processes that are actually using the mount point first? One some machines, I killed more or less everything. It didn't help. One some other machines, I couldn't kill so blindly. Remember, both "lsof" and "fuser" hangs. Also, as far as I understand, Solaris 8 does not require that you kill all processes before unmounting, if you use the "-f" flag (processes will get EIO). Would it be possible to implement this feature in Linux? That would be really nice. Regards, Peter >>For as long as I remember, umount -f has been broken. I got a reminder >>of this fact today when we took an older NFS server out of use. I had to >>reboot almost all machines that had mounts from this server. Not nice. >> >>Anyone knows why -f does not work? When I try, I get: >> >># umount -f /import/applix Cannot MOUNTPROG RPC: RPC: Port mapper >>failure - RPC: Unable to receive umount2: Device or resource busy >>umount: /import/applix: device is busy >> >>lsof and fuser hangs, as do "df" and "du". Really frustrating. It's not >>even possible to cleanly reboot the system, since RedHats shutdown >>scripts wants to unmount NFS fs's. >> >>I'm not exactly sure I understand what -f is supposed to do. Is it >>correct that it is supposed to unmount without contacting the NFS >>server? I assume that I still have to make sure no processes are using >>the FS? Would it be possible to add a "-9" flag (or something like that) >>that kills off all processes that uses the NFS fs automatically? >> >>(I'm using all kinds of RedHat Linux versions, from 5.0 up to 7.3. From >>what I can tell, this problems exists in all versions.) >>