I have a CentOS 5 VMWare server connecting to an OpenSolaris 2009.06 machine over NFS that holds the disk images. My virtual machines seem to be bound by slow IO so I'd like to do everything I can to optimize the connection.
I'm not sure of the best way to measure the throughput on a production system, but some unscientific tests using
dd bs=1024k count=400 show local (OpenSolaris) writes of ~1.6GB/s and remote (CentOS) writes ~50MB/s. I imagine these are lower than what I'm actually getting since 7 VMs are currently running over the connection.
Currently, the 2 machines are direct-connected gigE with jumbo frames enabled on both NICs (MTU=9000). Other than that, no optimizations have been made. NFS mount/export is using defaults.
Where should I start turning knobs to improve the performance?