VMotion : CPU Compatibility - Identify Feature

[craigal]

I have an existing cluster of 2 Servers running 3.5u1.

Both of these servers are DELL 2950 Series 3 servers with 32 GB of RAM. On both of these servers on the configuration tab the processor model is shown as

Intel(R) Xeon(R) CPU E5440 @ 2.83GHZ

I have purchased another DELL 2950 Series 3 server to add to the cluster. The processor model shows exactly the same string.

I have installed ESX to the same version and patch level of the existing servers. When I try to VMotion a VM to this new host I get an error saying that the CPUs are not compatible. The exact error is attached to this post.

I am assuming that there is some bios feature that is set differently on the new server caompared to the old servers. Because of the load on the existing hosts I cannot VMotion all of the VMs to the other host. This means I cannot reboot one of the existing hosts to check the BIOS settings.

Is it possible to determine from the error message what CPU feature is missing or set differently?

Craig

[dkfbp]

Hi,

The most common changes in the bios are:

1. "Intel virtualization Technology" - Enable

2. "Intel execute disable bit" - Enable

Check on your old and new host that they are the same

Best regards

Frank Brix Pedersen

[craigal]

Frank,

Thanks for your reply.

Originally, the IVT was disabled when I first saw the error. I enabled this but the error stayed.

The execute disable bit was enabled. I trid to disable this but received a quite specific error when doing a vmotion so I enable it again.

The problem is that I cannot reboot the existing hosts.

Craig

[jose_maria_gonz]

Hi craigal,

Have you checked the Dell VMware compatibility guide?

http://support.dell.com/support/edocs/software/eslvmwre/AdditionalDocs/VMotion_Matrix/48704A01.pdf

As far as I can see the Intel Xeon 54xx Series is VMotion compatible with 53xx, 52xx and 51xx Series

rgds,

Jose Maria Gonzalez

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[craigal]

Jose,

thanks for your reply.

The new server is the same model as the existing 2 servers

Cheers

Craig

[craigal]

I have been able to determine some more information from these servers.

The new server has the same processor but a slightly newer stepping number

Old Server: Model 23 Stepping 6

New Server: Model 23 Stepping 10

Would this be enough to cause the VMotion incompatibility

Also, the BIOS on the new server is newer

Old Server: Bios 2.3.1

New Server Bios 2.5.0

I checked the release notes for the bios upgrades from 2.3.1 to 2.5.0 and found the following which I thought may be relevant from the Bios 2.4.3 release notes.

• Added support for Quad-Core Intel(R) Xeon(R) Processor 5400 series E0 Stepping

• Updated Quad-Core Intel(R) Xeon(R) Processor 5400 series C0 Stepping Microcode

Does anyone know if these could be the cause of the problem? If so then a BIOS upgrade of the old servers will fix the problem.

Another option I have is to enable the EVC (Enhanced VMotion Compatibility) feature on VMWare which requires an upgrade to ESX to at least Update 2. This would mean a major fast-track of my planned upgrade to ESX 3.5 update 3.

Craig

[rubensluque]

I had the same problem in the past but the hardware were both IBM servers System X 3650. I've solved that by upgrade firmware BIOS to the last level version on both servers.

regards,

Rubens

[craigal]

The issue was caused by the change in the stepping value of the CPU.

I found another server here to use that has the same stepping value as the existing servers but with the newer BIOS. This server worked with VMotion.

I will be upgrading all of our ESX serers next month. I will then enable the EVC feature which hopefully will overcome this issue in the future