Re: NFS random "permission denied"

[Michael Loftis <mloftis@modwest.com>]

--On March 22, 2007 10:58:29 AM +0000 Dan Wade <dan.wade@kcl.ac.uk> wrote:

> Hi -
>
> Forty NFS client workstations running Debian etch and sarge, am-utils
> automounter, a dozen active users.  Server is Debian sarge on Dell
> PowerEdge 2850, PERC, Raid-5, stock kernel 2.6.8-2-686-smp.  Runs just
> fine for about 3 months, then starts randomly saying "permission
> denied".  nfs-kernel-server restart doesn't fix it.  Reboot has worked
> on both of two occasions, but 3 months later it starts "permission
> denied" again.  If there's an error in /etc/exports, I can't see it.

You're lucky, for us we hit it in minutes during our peak loads.  It's a 
2.6.8 kernel bug somewhere.  I suspect in the inode lookup code or cache, 
I'm pretty sure it exists as late as 2.6.10 but never tested further than 
that as I couldn't replicate it except by putting my production NFS 
environment under the gun.  I'm glad I'm not completely insane and I'm not 
the only one seeing it atleast.  Our solution was to go back to 2.4.x 
kernels for the NFS server.

> Googling found a couple of similar reports, but no obvious course of
> action other than checking /etc/exports.  If I've got an error there, I
> can't see it.  Sorry, can't publish - security.  In any case the
> symptoms don't mesh with a syntax error.  What should I do?
>
> - Dan