Conference smurf::nfs

479.0. "Usenet News Servers and READ ONLY NFS perf." by GYRO::faux.zko.dec.com::skinner (Internet Business Group) Fri May 16 1997 14:37

Hi,

One of the more popular ways Internet Service Porviders runs a news
server is by nfs mounting the news spool area to "client machines".
These client machine(s) are the machines that the news readers 
actually connect to, usually via round robin DNS. The news reader
daemon (nnrpd) is spawned from inetd.conf when a reader connects
to port 119. It is launched in such a way that the daemon knows
that any new posting the reader does, goes back to the host
that actually owns the news spool area. So the spool area is mounted
READ ONLY.

The average news article is about 3K in size. The average alt.binary
is usually about 900K in size. Alt.binaries can be up to 25%
of a full feed. A full feed is about 20 gig a day.

If I mount the news spool area READ ONLY on the client machines,
what is the performance degradation? A customer may have from 1
to 3 of these client machines. Any issues there? Any rules of
thumb?

In this scerario, any NFS kernel parameters that can be tuned?

Also, in a nutshell, can someone explain how Digital's NFS
does caching? Can you tune the kernel on the client machines to 
affect how much NFS caches? The client machines usually have
LOTS of memory.

Thanks for any info/pointers.

Shari