topic Re: Stale NFS mounts in Operating System - HP-UX

Stale NFS mounts

mike adams_4 — Mon, 18 Oct 2004 08:56:27 GMT

What is the best way to resolve stale NFS mounts? This occured when rebiulding the NFS server and now the client is reporting stale mounts.

Re: Stale NFS mounts

G. Vrijhoeven — Mon, 18 Oct 2004 09:00:30 GMT

Hi Mike,

check this link:

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B1031-90053/B1031-90053_top.html&con=/hpux/onlinedocs/B1031-90053/00/00/47-con.html&toc=/hpux/onlinedocs/B1031-90053/00/00/47-toc.html&searchterms=stale%7cNFS%7cmounts%7cresolve&queryid=20041018-075947

Regards,

Gideon

Re: Stale NFS mounts

Pete Randall — Mon, 18 Oct 2004 09:00:33 GMT

Mike,

The only way to really resolve stale mounts is to reboot. With the latest versions of HP-UX and NFS, this problem seems to happen less frequently - you might want to consider updating and/or patching NFS.

Pete

Re: Stale NFS mounts

RAC_1 — Mon, 18 Oct 2004 09:01:28 GMT

With new NFS version, there is a provision to forcibly unmount stale NFS moounts. If you not have that, your only option is reboot.

You should be moutning the NFS mounts with soft option, so that you atleast get to work.

By default they are mounted with hard option.

Anil

Re: Stale NFS mounts

Chris Wilshaw — Mon, 18 Oct 2004 09:03:14 GMT

To refresh the mounts, you'll need to unmount each one from the client, then re-mount them (mount -a will do this as long as they have been defined in /etc/fstab.

Ideally, you should unmount them from the client before working on the server (of course, if the server crashed, you wouldn't have a chance to do this).

Re: Stale NFS mounts

V. Nyga — Mon, 18 Oct 2004 09:53:53 GMT

Hi,

umount -a
and then
mount -a
should work
If not, then you have to look for the process which still accesses the directory.

Volkmar

Re: Stale NFS mounts

Govind_3 — Mon, 18 Oct 2004 12:59:40 GMT

The best and the easiest way is to reboot the NFS clients, after the NFS server is rebuilt, to remove the stale NFS file handles.
The harder way is to however unmount the file system on the client and remount it.
Cheers,
Govind

Re: Stale NFS mounts

Bill Hassell — Mon, 18 Oct 2004 21:01:51 GMT

NFS is very difficult to handle when server or network problems exist. In essence, when the NFS server(s) went down, it was as if you yanked out a physical disk. There may be processes with open files, directory searches from the filesystems, user shells cd'ed into these directories, etc. So a lot of code needs special handling for loss of files and directories.

With the next release of HP-UX, an NFS forced umount may be available. But for now, NFS servers can never be shutdown until all clients have umounted their NFS mountpoints. This is one of the reasons to use NFS with caution on production servers.

Re: Stale NFS mounts

Muthukumar_5 — Tue, 19 Oct 2004 00:05:27 GMT

Some human checks or automated scripting there.

Check particular Stale mount and unmount that with umount

Another key one is, if some user is on Staled directory then that will be a more problem. We have to tell the logged users to come out of that directory to unmount that FS there.

Simply removing entry from /etc/mnttab may be also used there.