View Full Version : [ubuntu] NFS performance - client timeouts

August 29th, 2012, 04:39 AM

I have a pretty busy NFS server on 12.04. We are seeing client timeouts such as:
nfs: server omadvnfs01-nfs-a not responding, still trying
nfs: server omadvnfs01-nfs-c not responding, still trying

1. We are using MTU 9000
2. Mounting with these options: defaults,noatime,nodiratime
3. Exporting with these options: rw,no_root_squash,async,no_subtree_check
4. Modified RPCNFSDCOUNT in /etc/default/nfs-kernel-server to be 64.

We push around 650 Mbps through this server using 802.3ad bonded nics. But hit up to 1 Gbps speeds. I think our clients need to send more. Any ideas?

August 29th, 2012, 04:02 PM
Try adding "rsize=32768,wsize=32768" to the client's list of options in fstab. You might try upping the values to 65536 or even higher and see how performance is affected.

Take a look at this document (http://nfs.sourceforge.net/nfs-howto/ar01s05.html) for more information on optimizing throughputs.