NFS under load?

        I've been meaning to figure this out for a while now. Between two
Linux machines (one exporting an NFS file system), I go to copy a large
(couple gb) file. Both machines are plenty fast, have lots of RAM
(gbs), and have SATA drives of a reasonable calibre. I see transfer
rates of 8 to 15 megabytes a second. Then I get a stall, and the entire
thing starts to slow down to an average of 10 megabytes a second. The
load on the server (which exports the fs) goes up to 8 or 9, while the
client remains at a reasonable fraction of a user.
        What is wrong with how I have NFS setup? It seems that adding more
nfsd processes just leads to RAM/CPU contention and further exacerbates
the stalls.
        Any suggestions on how I can tune NFS for gigE use?
Received on Mon Jul 2 21:35:15 2007