[PLUG] How to umount NFS hung mouts

[Terry Griffin]

On Wed, Aug 13, 2003 at 10:58:11AM -0700, Terry Griffin wrote:
> On Wed, Aug 13, 2003 at 09:40:13AM -0700, Alex Daniloff wrote:
> > Hello Linux folkz,
> > Could somebody tell me please
> > how to safely umount locally mounted NFS share
> > when remote NFS server is down?
> > Rebooting local machine is not an option in my case.
> > 
> > Thank you in advance.
> > Alex
> > 
> 
> This won't help you now, but if you run in to this problem a lot
> because of an unreliable network, unreliable server, or whatever,
> you might want to mount your NFS shares with the "soft" option.
> Shares mounted in this way are easier to deal with when the server
> is unavailable. Any attempt to access the NFS file system will
> time out instead of hang.
> 
> There are supposedly some down sides with the "soft" option. The man
> page is vague about this, but I suspect it has to do with undesirable 
> timeouts resulting from a merely busy network or server as opposed to 
> something actually being down.
>

I just gave myself an idea. It's a long shot, but try re-mounting the
NFS file system using the "remount" option thusly:

   mount -oremount,soft /mnt/nfs-share-in-ca

The "remount" option doesn't to a full unmount and mount, so it just might 
apply the "soft" option to the mount point without getting hung up trying 
to communicate with the server. If it works, then you might be able to 
unmount the share outright. Or even if not, it should cause less trouble
until the server comes back.

Terry
-- 
Terry Griffin <griffint at pobox.com>
http://www.blindchicken.com/~terryg/