Can I make a guest that sees 2 physical CPUs and 4 logical? (i.e. dual core)

[lwarner]

I have several PE2950s dual socket, dual core that were running ESXi 3.5. I've started migrating to ESXi 4 on a Dell R900, quad socked 6-core. I have one application (InDesign Server) under Win2003 that is licensed per CPU; on the PE2950s, when I assigned 4 virtual CPUs, the app saw 2 physical CPUs and 4 logical. This allowed the program to run, as it looks for "2 CPUs" and I'm assuming that it looked at the logical CPU count, but it processed 4 simultaneous threads, one on each core (this is how it's supposed to function). However, when I moved the VM to the R900 and assigned 4 vCPUs, it saw 4 logical and 4 physical, and the app refused to run. I can assign it 2 vCPUs, but then it will try to run 2 threads per core, giving me only half the speed.

So the question is, can I get the guest VM to see a "dual core" CPU? If I can assign it 2 dual-core CPUs, it would solve my issue. Thanks!

[mvoss18]

It sounds like the app was able to take advantage of hyperthreading on the 2950. I don't believe you can enable hyperthreading on the six core CPUs on the R900 so you may be out of luck. You may see increased performance anyway because the R900 has so many available cores. With the 4 core 2950, running a VM with 2 vCPU would chew up a lot of CPU time.

[K-MaC · Accepted solution]

Hello please see the following page for a solution to your problem

http://www.yellow-bricks.com/2009/06/04/per-processor-licenses-for-your-application/

If you found this information useful please consider awarding points and or marking the thread answered.

Cheers

Kevin

[lwarner]

Kevin, that's exactly what I needed, thank you! I set my guest to 4 vCPU, set the number of "cores" to 2, and now the guest sees 2 dual-core CPUs, and the application process correctly. Also, this answers my question about what to do with my SQL server, since it's licensed per socket, and I have a single socket license. My SQL is running on a quad-core physical box, and now I know what to do when I go P2V.

mvoss, my PE2950s did not have hyperthreading-capable CPUs, so I'm not exactly sure why I got "dual-core" CPUs in my guest VM... although I would be interesting in knowing why. I'll probably do some further reading on this.

[K-MaC]

Hey. Glad I could help you out. Although I can't take credit for this. Those honors go to Duncan Epping and his great website for all things VMware www.yellow-bricks.com.

I am looking into the future of your SQL server and I get the feeling it will be running on a 4-8 core 'single socket'.

As for finding out why you had a 'dual core' on your old server I would suggest posting the .vmx file here and asking around. Unfortunately, my VMware skills are not sufficient to let you know. However, there are a tonne of people around here that can likely help you.

Have a good weekend.

Cheers

Kevin