File Server Performance Problems: Windows 2008 DataCtr - 32 Bit

[rvanthiel]

We successfully migrated some Netware data to a new Windows VM last weekend. We are seeing some performance issues with constant CPU spikes and it's just the "system" process that spikes it. Wondering if anyone has seen something like this before, has ideas, or any known compatibility issues?

The VM has 2 vCPU and 3GB of RAM allocated to it. As of right now, there are just 123 users connected with about 500 files open.

Attached "Screenshot3" is what it looked like about 6am this morning when few users are logged in, looks perfect. "Screenshot4" is what it looks like now that users are on the system and it will stay like that all day long. Certainly doesn't seem right to me. Any thoughts?

We're running ESX3.5 Update 3 hosts. No contention on the hosts.

Thanks!

[JonT]

You are running Windows 2008 with only 3GB of memory? I would first of all recommend you increase to 4GB of RAM. Second you should use Perfmon to check and see if there is excesive paging going on at the kernel level because with the average load you stated the machine is doing an aweful lot of CPU work. Also check the network adapter and queues on the NIC to make sure it isn't passing some work off to the CPU's......if there are 500 files open consecutively you may also want to check the disk I/O. Does the system have all these files stored in a virtual hard disk, an RDM or a combination of both? There a plenty of things to check on this system but Perfmon should help you narrow it down some. My other question would be what type of host hardware are you using and what type of network and disk resources are physically connected?

Jon

[patrickds]

any special reason for having 2 vCPUs?

In general, you shouldn't use virtual multiprocessors unless required, since the overhead caused for the scheduler might actually degrade performance in the VM.

[jbogardus]

To get a proper view of CPU usage don't use Task Manager or Performance Manager. The CPU counters provided within the VM are not accurate. Use the Performance tab within VirtualCenter.

There are also new components of VMware Tools in vSphere which will add accurate counters to Performance Monitor. It's also possible to get it for ESX 3.5: