FreeBSD NFS Client, Windows 2003 NFS server

[Bruce Evans]

On Thu, 7 Dec 2006, M. Warner Losh wrote:

> We see FreeBSD to FreeBSD NFS feeling fast enough for most things, but
> when we do a full build of our system from scratch it takes 10 hours
> over NFS vs 1 hour on a local disk.

I have a report that lost dotdot caching seems to be responsible for
most of the enormous slowness of nfs under FreeBSD (for building a
large non-FreeBSD system), but I think this is only one of several
slowness factors, and building things in parallel is an adequate
workaround in all cases that I tried (mainly building kernels and
worlds).

> We're worried that if we were to
> try to do heavy NFS traffic to a Win2003 server with SFU this would be
> even slower.

The slowness in FreeBSD's nfs seems to be mostly in the client (except
network latency is in the network).  The client doesn't cache things
very well, so it generates a large number of RPCs so the total latency
= (per-RPC-latency * number-of-RPCs) is enormous if the per-RPC latency
is just large.

Bruce