VM consuming more cpu than the guest need

[therapie]

Hello

I have an issue I can not explain hope some one will give me clues tu help

I have 10 ESX 3.5 clustered with DRS

vc 2.5

2 of the VMs are consuming more cpu than the guests

while guest has an average of 5% cpu the vm has average of 30 to 50% cpu

2 days ago we needed to upgrade those VM from 1 to 4 cpu for them tu be able to restart

the DRS has isolated those 2 vms in one ESX for each

the gests are win 2000 advanced server with MS SQL 2k application but they are not the only ones in the infra

with esxtop I can see the host consuming for the 4 used cpu 30 to 50 % while the the guest is using (task manager) only 0 to 10

only one vm in the host

all ESX are same hardware

does someone have an idea on this issue?

and if not can someone give me clue or tool to help me investigate were the vm is using all this cpu

thanks in advances

[weinstein5]

Your descriptions raises a number of question - I am not sure why the VM would not start unless you add virtual CPUs? Since you did increase did you replace the HAL on your Win2K systems? - no a couple of points - the reason they are running on their own ESX server is more than likely because you went to four CPUs and the only way they could get the resources needed is to run on their own - Best practice is to run your VMs with a Uni virtual processor - were you have perfomance issues when they were uni processor? if not I would drop it back to a single processor and if they were go up to 2 virtual cpus before making the jump to 4 - you will still need to insure the HAL matches the number of cpus -

If you find this or any other answer useful please consider awarding points by marking the answer correct or helpful

[therapie]

Hello thanks for your post

here are the answers

the HAL was previously (whith 1 cpu) acpi multiprocessor so I did not changed it

all my win 2000 VMs are with acpi multiprocessor cause acpi uniprocessor is not availlable ... most of them have only one processor without errors so I did not changed anything to this.

I can not explain why those machines stoped to work with one cpu we tryied to restart them with 2 cpu and it was impossible (cpu saturation) we succeeded only with 4 cpu

I would like to bring back those vm to one cpu but first I want to answer this question why the vm is consuming from 30 to 50% of cpu while the guest is consuming only 5%

other thing one vm is rebooting every day so the host's consumtion of cpu is hight but stable (vm is alone in the host)

the other one is rebooting every week and the evolution during the week of the host cpu consumption is increasing regularly (vm is alone in the host too)

this seems to tell that some thing in the vm configuration or in the guest configuration force the vm to take more cpu ressources than needed by the guest processes and I would like to know what

hope I am clear enough

Daniel

[gechurch]

KB1077 may explain the CPU usage.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1077