Spontaneous reboot with 2.6.10 and NFSD

[Kim Holviala <kim@holviala.com>]

I hit an obscure bug last night when trying to copy files from an nfs 
client to my nfs server. The server is a P3/800 with three IDE disks in 
software RAID5 running vanilla 2.6.10 and Debian Sarge. The network is 
local 100Mbit/s switched ethernet. The server exports a 220 gig 
partition which contains a lot of data.

Oh, kernel configs and stuff from the server can be found from:
http://www.holviala.com/~kimmy/crash/

Anyway, I mount the export to a Linux client (tried with a few with 
different 2.6 kernels and distros) and then start copying files from 
clients CDROM to the server through NFS. After copying a few small 
files, the first big one reboots the server. There are no log entries, 
and the server has no local console so I don't know what happens. This 
is reproduceable 100% of the time.

To narrow down the problem, I've tried the following:

- copied files from a different client running Gentoo: reboot
- exported a non-raided partition (hdc9) and tried that: reboot
- switched 2.6.10 to 2.6.11-rc3: reboot, but it took longer

I hope it's just something that I've done, but this server has been in 
use for a long time now without any problems, and I haven't touched it 
for a while.

So, if anyone knows what's wrong, or can tell me a way to debug the 
situation more I'd be grateful. The server is in a place where it's 
nearly impossible to have a local console - I could probably use a 
serial one if necessary for debugging.



Kim