Intel CPU incompatibility

[pshearduk]

Hi,

We are using an IBM H class chassis which initially had 3 x HS21 blades all using the Xeon X5355 family of CPU. We have since added another 3 x HS21 blades but which are now using the Xeon E5430 processors. Now although I was aware of CPU incompatibility between AMD/INTEL CPU's for VMotion, I was not aware of the different processor but same manufacturer problem. I can work around this and have used this as an excuse to create a new resource pool and can move existing VM's accross with a cold VMotion, so this is more of an inconveinience than anything else..

However my question to the community is if anyone know's if VMware are working with INTEL/AMD to implement some sort of compatibility between both the same manufacturers processors, and (dare I say it) between INTEL & AMD manufacturers. Also if they are working on this, is there any expected date? quarter? year??

Any advice appreciated

Paul.

[kjb007]

Intel and AMD have created technology that will allow compatibility within the vendor itself. Intel calls it FlexMigration and AMD calls it Extended Migration. They allow the newer cpu's to dumb down their feature-set to be vmotion compatible with the older processors. This doesn't allow AMD-Intel or vice versa, but it does allow you to buy newer processors and have the be compatible within your cluster. I can't speak to how well this actually works, as I haven't tried it, but support for it is there now with Update 2, called Enhanced Vmotion Compatibility inside of ESX 3.5 U2.

-KjB

[wpatton]

Paul,

With ESX 3.5 Update 2, you can now add all these systems to a cluster with Enhanced VMotion enabled and it will allow for migration between all hosts. However, that said, it does require an outage for each system to be added to this cluster for EVC support to be enabled. (Of course the obligatory GOTCHA)

From Update 2 Release Notes:

Enhanced VMotion Compatibility - Simplifies VMotion compatibility issues across CPU generations. Enhanced VMotion compatibility (EVC) automatically configure server CPUs with Intel FlexMigration or AMD-V Extended Migration technologies to be compatible with older servers. After EVC is enabled for a cluster in the VirtualCenter inventory, all hosts in that cluster are configured to ensure CPU compatibility for VMotion. VirtualCenter does not permit the addition of hosts that cannot be automatically configured to be compatible with those already in the EVC cluster.

[pshearduk]

Thanks for the prompt answer gents, can I ask how the EVC is enabled? I am running VI3.5 update 2 but cannot see where/how this is configured?

[kjb007]

Edit your cluster settings. One new option will be there for ' VMware EVC'. It requires all vm's to be down. You will need the hardware functionality as well to mix processors, but you can enable it beforehand. It will only allow you to add servers into the cluster that are compatible with vmotion.

-KjB

[prashantprahlad · Accepted solution]

VMware has been working with Intel and AMD on including hardware support for Live Migration. The new EVC technology in ESX 3.5Update 2 uses this technology to make CPUs across different generations compatible

EVC will ensure that Intel CPUs based on the Penryn architecture (the latest Intel CPUs) will be compatible with Intel CPUs based on the Merom architecture (like Tigerton, Clovertown, Woodcrest, etc). On the AMD side, Third Generation AMD Opteron CPUs (Barcelona) will be made compatible with Second Generation AMD Opteron CPUs (Rev.E/Rev.F)

Note that Intel CPUs prior to Merom (such as Tulsa, Sossaman, and others based on P4 or NetBurst architectures) are not allowed in an Intel EVC cluster. Similarly, AMD CPUs prior to Second Generation AMD Opteron (such as Rev. C, Rev. CG, etc.) will not be allowed into an AMD EVC cluster.

You can look at the Chapter 15 of the Basic System Administration guide for details

http://vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_admin_guide.pdf

[pshearduk]

Great!! :smileygrin:

Many thanks for all the information, very much appreciated

Paul

[kjb007]

Don't forget to leave points for helpful/correct posts!

-KjB