Seek advise: VMmotion migrating problem between Hosts with diferent CPUs

[BMS-Mann]

Hi,

we have addet 2 additional hosts to our existing VM-envinonment. Unfortunately the hosts had diferent CPUs, so the migrating between the old and the new hosts doesn't work properly any more.

I know that i can fix this with a ESX 3.5 Update 3 or 2. (We have 4 esx 3.5 hosts with 2.5 Virtual Infrastructure Server. No Updates)

I tried to migrate a Powerd-off VM and except of a warning "Migration will cause thevirtual machine's configuration to be modified, to preserve theCPU feature requirements for its guest OS" there was no Problem with it. I was able to power it on, work with it. I could see the other hosts, everithing was fine.The only thing i couldn't do is to migrate the Powerd-on-VM from a new host to an old host. That was merely a test.

For the next 10 days we dont need HA so badly, because we have to test a software with our VM's. That is our top priority.

Is there a reason why i shouldn't migrate all our VM's to the new hosts and wait with the update 3 for 10 days?

[JoJoGabor]

Enhanced Vmotion Compatibility (EVC) was introduced with either update 2 or 3 (I cant remember which) which allows VMotion to happen between different processors. However only the latest servers are capable of doing this. I believe all HP Proliant G5 servers are capable, and you will need to enable VT extensions and another setting in the BIOS to enable this on the ESX servers in the cluster. Then you can VMotion between the two. If you have older servers tey will not allow for EVC to be used.

[Erik_Zandboer]

Hi,

You state "you don't need HA for the next 10 days".... Do not mix up the two of them! With incompatible CPUs, HA will still work. Only the vmotioning of VMs (and therefore also DRS) requires compatible CPUs.

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[BMS-Mann]

@ all: Thank you for answering.

I've updated our VM-Environment. It works great now.