vMotion between 2 hosts

[rayan68]

Hi

I have 2 hosts in my vmware farm has  the same hardware as follow

HP Proliant DL 585 G5

Model: 16 CPUs x2.31 GHz

Processor Type: Quad-Core AMD Opteron(tm) Processor 8356

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for example host01 and host02 , I can vmotion from Host01 to host02 any vm , but not from host02 to host01 , it gives me CPU issue

I cannot find any reason as the CPU in both hosts are the same , any idea ?

[a_p_]

It looks like one of the hosts doesn't have NX/XD enabled in the BIOS.

Make sure the BIOS setting on both hosts are the same.

André

[marcelo_soares]

You can use the CPU Identification Utility to check what is different between the hosts:

http://download3.vmware.com/software/vi/VMware-CPU-Compatibility-e.x.p-160658.zip

Boot each physical host with this ISO and check the difference. If in doubt, post the output here.

[bugblatterbeast]

I'm going to make a guess here but it sounds like you have no clustering between the 2 hosts and therefore no EVC enabled.

What is probably happening is that when you boot a VM on Host1 (which has a lower generation of CPU with less features) you are able to to vMotion to Host2 as it can handle the CPU feature set the VM is booted with.  In theory (as long as you don't power this VM off) you should be able to vMotion this VM back to Host1.  If you boot a VM on Host2 then it has the extra CPU features that Host1 cannot satisfy and therefore vMotion to Host1 fails.

The simple answer is cluster the 2 Hosts together and enable an EVC mode that both Hosts can satisfy.  I advise powering down any VMs booted on Host2 first and (if you have capacity) boot them on Host1 to allow this to happen.

Danny

[TomHowarth]

the original poster stated that the machine were identical.

"I cannot find any reason as the CPU in both hosts are the same , any idea ?"

I am more for the view that there is a bios difference between the two hosts,  as Andre and Marcelo stated, use the CPU identification utility to check