Urgent :esxi 5.5 1331820 , guest OS cpu usage 100%, Host cpu at 20%

[hasidere]

I've got ESXI 5.5 with currently only one VM- it's sbs2011.

Hardware is Dell t420 , Xeon e5-2420 @1.9ghz, 1 socket, 6 cores, 12 logical procesors.

For this virtual machine I've allocated 2 sockets with 3 cores, so 6 vCPUs.

This setup has been working for the last 6 Months, but since yesterday guest OS is maxing with 100% cpu. In vsphere client I can see that the gust is only using 1000MHz, from 12000Mhz available?!

How can I make the guest to use more than this?

Obviously guest is almost unusable, being so slow.

[nettech1]

if you haven't killed it yet, is CPU usage at 100% when you boot it in safe mode?

what antivirus is installed on this guest?

Edit: just saw trend micro client. did you set up antivirus exclusions per MS KB  http://technet.microsoft.com/en-us/library/bb332342(v=exchg.150).aspx ?

[atomey]

Not sure if you're still having this issue but I experienced a very similar issue. We are running a Dell PowerEdge R420 with the same build of ESXi 5.5, 1331820. We had guest VMs getting 100% CPU usage and nearly unuseable.

The solution ended up being disabling DBPM for CPU power management. This is demand-based power management within the Dell BIOS. This immediately solved this issue. I recommend setting the machine to high performance if you're seeing this issue.

There's a VMWare article that mentions this:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=101820...