NFS performance for virtual machines
68077Dec 8 2008 — edited Jan 24 2009HI All,
I am doing some tests around the usability of Oracle VM. Initial tests on a 2 machine setup. 1 server and 1 manager have been great.
However we wanted to use server pools.
To do this we moved our /OVS directories to a NAS server which has a hardware sata raid 5 card. I can write locally to this at 160Mb per second which is quite accepatble. Reads tend to be faster. The problem seems to be that the maximum write speed I can get over NFS is around 44mb per second. This has a detremental impact on any file based operations from within the VMs.
I believe I can speed this up significantly if I use the async option when exporting the file system from the NAS but this would most likely leave me open to corrupting a virtual machine if the NAS failed.
Does anyone have any ideas on the best way to configure this setup? I have 4 machines available.
1 x NAS on Oracle ES linux 5 with raid disks
2 x VM Servers. 16gb ram quad core cpus
1 x OVS manager 2gb ram dual core cpu
I'm very confident that disk IO over NFS is my bottleneck.