Optimum NFS Settings for Xen DomU


I have a couple of Xen linux domU pv vms running on Xen 3.3.1. They boot via NFS from the Xen host.

They also have /home mounted via nfs which is also located on the Xen host, and I am seeing very slow performance - particularly with Maildir access via courier imap, or by mutt directly.

There is only one user currently, so not much load.

I am using the following mount options:

rw,bg,hard,rsize=32768, wsize=32768,tcp,vers=3, timeo=600,tcp

Any tips on getting this up to speed? The virtual interface is gigabit, so I would expect this to be almost as fast as directly accessing the disk.