I'll be testing with a different brand of NIC shortly on that server, but in the meantime I've just used two spare workstations to create identical Solaris and W2k3 server NFS server, and on those the windows server has faster write speeds. On a machine with a single hard disk and a 100Mb NIC I'm getting read speeds of 10MB/s and write speeds of 6.4MB/s. The Solaris server running on an identical machine is giving read speeds of 10MB/s and write speeds of 2.2MB/s.

So from that test, it appears W2k3 server is capable of decent NFS performance, certainly comparable to a default Solaris install. However I really shouldn't be getting the same write speeds from a workstation with a 100Mb NIC and a single IDE hard disk as I get from a dedicated server with a gigabit NIC and 15 SATA drives running off a battery backed raid controller with write caching enabled...

My current plans are to:

• Fit gigabit NIC's to the test workstations, and test Solaris and W2k3 NFS performance using those.
• Fit the same brand of gigabit NIC to the original server and see if the performance changes.

I'm also reading that NFSv3 now support asynchronous writes and that this has a major effect on performance. Unfortuantely I can't force async mode on the W2k3 server, does anybody know if it's possible to configure the NFS client within ESX to use async writes?

Incidentally, I just tested performance on the workstation installation of W2k3, with a d-link gigabit NIC, and I'm getting 46MB/s read and 27MB/s write performance. I'm about to fit one of those NIC's to the original server now, but I'd still like to try mounting NFS differently

With a standard hard disk I was still getting timeouts, so that got me thinking about what else might be different between the server and the workstation I'd tested NFS on. Well, one major difference is that the server has two quad core Xeon processors, so I decided to try forcing the NFS service to just use a single core. I set the "Server for NFS" service to logon using a network account, restarted it, then used Task Manager to force "nfssvc.exe" to use processor 0 only.

Started the re-installation on the virtual clients and they flew through the formatting. The raid card still appeared slower than the single drive, so I'll carry on testing that, but you could actually see the difference on the HDD activity lights. Whereas before the lights just flickered on briefly and you could see it walking through the drives during the format, now every I/O light is on solidly while XP is formatting the disk. I was concerned about CPU load, but I've not even seen that processor go over 1% usage yet, so it appears a single core will be fine.