What EVC mode to choose for these specific CPUs

[MartinF10]

Hi,

how can I find out what EVC mode should I choose for these CPUs (4.1U3) ? Because I changed HW of one host, I created another cluster with EVC enabled. Before I start to cold migrate the VMs from the original cluster, I would like to verify if I have chosen the right EVC mode.

CPUs:

- Xeon X3430

- Xeon E5504

- Xeon E5-2407

My clusters right now are

1. cluster - EVC disabled - Xeon X3430, Xeon E5504

2. cluster - EVC Intel Xeon Core 2 - Xeon E4-2407

I am afraid that after I cold migrate VMs to the new cluster, and add machines to the new cluster, I will still not be able to do live migration.. So I will have to recreate another cluster with another EVC..

[Fabian Lenz]

Create you EVC cluster and include the "oldest" CPU generation. Create a new test-machine and try to migrate it to the newer host.

If I'm right all of your CPUs are nehalem and sandy bridge architectures, which means that you can set your baseline to "nehalem"

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003212

[Sreejesh_D]

- Xeon X3430

Its a Intel Nehalem generation processor. Hence It falls under EVC level 'L2' and EVC Base line 'intel® "Nehalem" Gen. (formerly Intel® Xeon® Core™ i7)'.

- Xeon E5504

This too an Intel Nehalem generation processor. Again a EVC level 'L2' and EVC Base line "intel® "Nehalem" Gen. (formerly Intel® Xeon® Core™ i7)" candidate.

- Xeon E5-2407

Its a Intel Sandy Bridge generation processor. It falls under EVC Level 'L4' and EVC Base line "Intel® "Sandy Bridge" Generation".

The higher level EVC baselines will support the processors from lower baselines. Pls refer the KB mentioned previous comment ie, KB http://kb.vmware.com/kb/1003212)

In general, if a processor can support EVC level XN, it can also support levels XN-1 to X0. For example, a processor that supports the Intel® "Sandy Bridge" Generation EVC Baseline has an EVC level of L4. Therefore, it can also support EVC levels L3, L2, L1, and L0. However, it cannot support EVC level L5, which corresponds to the Intel® "Ivy Bridge" Generation.

so the ideal EVC baseline for your cluster is "Intel® "Sandy Bridge" Generation".

Note: the following wiki will help you to find the archtecture (eg: sandy bridge, nehalem etc) of a intel processor.

http://en.wikipedia.org/wiki/List_of_Intel_Xeon_microprocessors

[MartinF10]

Oh, I realized, that I will also change the oldest X3430 to E5-2407.

So the final configuration will be:

1x Xeon E5504

2x Xeon E5-2407

[Sreejesh_D]

Ok, still the recommended baseline is "Intel® "Sandy Bridge" Generation". because this baseline support both L4 (E5-2407) and L2 (E5504) EVC levels.

[Fabian Lenz]

are you sure? How can the Nehalen CPU run in the Sandy Bridge EVC mode?

it's correct that an L4 CPU can run in L1,2,3,4 .... but an L2 CPU can't run in L3,4,5 which means that the Nehalem (L2) can't run in the Sandy bridge (L4) mode.

Do I have any mistakes in my thinking?

[Sreejesh_D]

Thanks lenzker, thats correct. Nehalem genartion processors are not supported in Sandy-bridge. the formula you explained is the right one, i've misinterpreted  the explanation in KB.

We can do two things to confirm the EVC mode.

1. Use the VMware compatibility guide web app. It will tell the supported EVC mode. In this select the option "Search by EVC mode" and give the processor as keyword.

http://partnerweb.vmware.com/comp_guide1/search.php?action=base&deviceCategory=server

2. User VMware CPU identification utility.

http://www.vmware.com/download/shared_utilities.html

[MartinF10]

I'm not sure if vCenter 4.1 U3 supports sandy bridge generation - http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003212