craigal
Enthusiast
Enthusiast

VMotion : CPU Compatibility - Identify Feature

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

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7 Replies
dkfbp
Expert
Expert

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

Best regards Frank Brix Pedersen blog: http://www.vfrank.org
craigal
Enthusiast
Enthusiast

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

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jose_maria_gonz
Virtuoso
Virtuoso

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

If you find this or any other answer useful please consider awarding points by marking the answer helpful or correct.

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El Blog de Virtualizacion en Español

http://josemariagonzalez.es

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craigal
Enthusiast
Enthusiast

Jose,

thanks for your reply.

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

Cheers

Craig

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craigal
Enthusiast
Enthusiast

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

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rubensluque
Enthusiast
Enthusiast

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
Enthusiast
Enthusiast

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

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