running really short an DMA buffers

[Christian Guggenberger <christian.guggenberger@xxxxxxxxxxxxxxxxxxxxxxxx>]

Hi,

I'm running Dual PIII 450MHz with 512MB Ram as an nfs server. System is 
Debian Woody. Kernel is cvs, checked out on June, 14th.
The machine ooopsd two weeks ago, but I wasn't able to reproduce with kbd, 
because another guy rebooted it.
I only saw a huge amount of "Warning - running *really* short on DMA 
buffers" kernel-messages.

Now these messages come again. Anything to be concerned of?

Some Details:
two filesystems on top of lvm 1.0.3 (each 200GB) are exported via NFS. The 
filesystems are mounted with "logbufs=8".

Is this value too high with "only" 512MB of RAM?

thanks in advance
Christian