Citrix VM CPU spiking

[chadd39]

I have a beefy host box.. dell poweredge 6800. Quad processor, dual core with 16 gb ram. I added one citrix server to it. nothing else. I built the vm from from scratch. After i get about 10 users on it, the vm's cpu use is around 70%. If only 5 people are on it, it runs around 50%. With 5 people on, if one of them does anything like open internet explorer, the cpu in the vm will spike for a second and then return to 50%...

The VM is configured with 2 virtual processors and 4 gb ram. 2 teamed 1gb nics. Users are only running Microsoft Office apps. On a physical 9poweredge 2650, 4 gb and 2 3.2 ghz proc, i can get 30 users per server with a cpu load of around 70%.

Am i missing something here. Is this the performance i should expect to see when running citrix on esx 3.0? Everything just seems slower than on a physical box. Internet explorer, clicking around in windows explorer...

I attached a pic of the cpu utilization graph

Thanks

[jayolsen]

If you are using 2 VCPUs they both need access to a physical CPU at the same time. So it would be possible that you are getting wait times on one VCPU.

Could you stand up another VM with 1 CPU and see if performance is better?

[khughes]

We run a citrix enviroment on our 3.0.2 esx hosts fine with 2 different types of servers, one is a duel quad core, with 16gb ram, and the other is a duel duel core with 16gb or ram

So your single quad core should match up with our duel duel cores, we run our servers with 2 vCPU's fine because Citrix is a multi-threaded app and we can get 30-40 users on one virtual machine so I would say there is something either wrong with the citrix build or esx host. are you running any resource pools that could be limiting the resources of the vm's?

[TomHowarth]

Do you have a real time AV checker running in your PS server, also what version of Office are your running 2K7 and 2K3 outlook can be real resource hogs. however personally I would check your context switches in your server to see of you have a high number also check ESXTOP to see what the numbers are there. if they are high consider dropping to a single vCPU (remember to change the HAL) as you may be getting a resource scheduling issue on the Host.

personally I would go for 2 vCPU CPS Guests rather than 1 2vCPU Guest. you will get better numbers. also have a look on www.DABCC.com and www,Brianmadden.com for hints and tips on Citrix optimisation. a base 2K3 build does not cut the mustard.

Tom Howarth

VMware Communities User Moderator