nfs performance issues.

[Jonathan Hirschman]

Tomoki Taniguchi wrote:
> I seem to be suffering some performance problems when transfering
> files over nfs.
>   
Here's my fstab line from one of my clients:

foo:/raid_local         /raid           nfs             
rw,hard,intr,rsize=65536,wsize=65536,nfsvers=3,tcp,async           0 0

You'll note that I use TCP and a very large block size - it worked 
better for me. I also run async (this is against best-practices 
suggestions - use at your own risk). Note that sync is the default, but 
it is slow.

Also- if you do interative performance testing tuning, you'll want to 
flush your caches between runs. You can flush the NFS cache by 
unmounting and remounting at the client. This may also be useful:

http://linux-mm.org/Drop_Caches

Good luck. It took me a while to get NFS running acceptably.

jh