Solved: Is modifying the CPU ID mask for SSE3 safe for VMo... - VMware Technology Network VMTN

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VMware does not support VMotion between SSE3 capable and non-capable hosts. It can be done, though.

A good description for it: http://kb.vmware.com/vmtnkb/search.do?cmd=displayKC&docType=kc&externalId=1993&sliceId=SAL_Public

What I'd like to know is,

\- what is your experience with vmotion migrations enabled by relaxing SSE3 compatibility checks?

\- on appx. how many different VM's?

\- how many failures/successes?

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for what i understand it's probably depends on your guest operating system and it's ability to change between 2 processor family's.

vmotion won't take the chance so when it detect 2 different cpu family it will prevent vmotion.

in esx 2.x and vc 1.x there was the option to disable the vmotion checking

in esx 3.x and vc 2.x i didn't find a way to disable the vmotion check only to apply the mask to each vm.

what i did is to crate a clone of vm for each os that i run and tested the mask

i tested windows 2003 and redhat 4 and didn't see any problem it moved between the hosts smoothly and didn't present ant error in guest os.

but when it was time to put the hosts in DRS cluster i didn't have the courage to combine sse3 and sse2 hosts in the same cluster though i imagine it probably work.

my concern was, what will happens if someone will build new vm and forget to apply the mask.

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for what i understand it's probably depends on your guest operating system and it's ability to change between 2 processor family's.

vmotion won't take the chance so when it detect 2 different cpu family it will prevent vmotion.

in esx 2.x and vc 1.x there was the option to disable the vmotion checking

in esx 3.x and vc 2.x i didn't find a way to disable the vmotion check only to apply the mask to each vm.

what i did is to crate a clone of vm for each os that i run and tested the mask

i tested windows 2003 and redhat 4 and didn't see any problem it moved between the hosts smoothly and didn't present ant error in guest os.

but when it was time to put the hosts in DRS cluster i didn't have the courage to combine sse3 and sse2 hosts in the same cluster though i imagine it probably work.

my concern was, what will happens if someone will build new vm and forget to apply the mask.

I tried the "build new vm and forget to apply the mask" scenario, what happened was that DRS attempted to migrate over and over again. Not a very nice thing I suppose. I might end up setting DRS to manual, as I'd like to combine SSE2 and SSE3 hosts in the same cluster.

I've made an entry in the config file for Virtual Center (running VC 2.0.1 with ES 3.0.1 Patch 2 hosts)... see thread.

http://www.vmware.com/community/thread.jspa?threadID=74844

For us this works smoothly vmotioning between DL585 and DL585 G2 servers.

I've done this, because we're not using 64 Bit OS

And you do don't have to "remember" flagging the vm's as you go, it's all configured in the Virtual Center config file.

Hey, good input tjuksa

I guess the story for DL580 G2 and G3 SSE3 will be something like this, then:

--::::::-x:-x-x</ecx>

</level-1>

</default-vendor>

</cpuFeatureMask>

</all-guests>

</all-versions>

</esx-3-x-x>

</guestOSDescriptor>

</vpxd>

</config>

I'm going to try this, will try to let you all know.

Message was edited by:

bjornl

yep, this works brilliant for me

as I have in my config we also needed to add the to more specific OS-es.

Of course it WOULD be nice to get some tech-guys from vmware to doc this option though... (pros / cons)