pbalderos
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Enthusiast

Unable to vMotion due to CPU Compatibility

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Hello All,

I am trying to vMotion between hosts in the same 2 host cluster because I want to do a memory upgrade. However host one has X5650 Westmere and the other host has a E5530 Nehalm.

It's important that I do not have to have any downtime in order to perform the vMotion so I went to enable EVC mode on the cluster and received the error shown in the second screenshot. So. I selected my oldest processor and instead of the error showing 2 hosts that are not compatible, this time it shows 1 host but am still unable to vMotion. Any solutions or tips you guys can provide?

EVC0.png

EVC1.png

EVC2.png

Phillip Balderos VCP6-DCV
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a_p_
Leadership
Leadership

There's unfortunately no way to archive your goal without downtime.

A VM is assigned the CPU features once powered on. Any VM that has been powered on on a host with a higher CPU feature set, cannot be migrated to a host with a lower feature set. Enabling EVC on a cluster requires that no VM with a newer feature set than what's presented by the selected EVC mode is powered on.

André

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a_p_
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Leadership

There's unfortunately no way to archive your goal without downtime.

A VM is assigned the CPU features once powered on. Any VM that has been powered on on a host with a higher CPU feature set, cannot be migrated to a host with a lower feature set. Enabling EVC on a cluster requires that no VM with a newer feature set than what's presented by the selected EVC mode is powered on.

André

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pbalderos
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Thanks Andre! I will ask for the down time. So, if I create another cluster and enable EVC on that cluster and move the host into it while everything is powered down that would work?

Phillip Balderos VCP6-DCV
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a_p_
Leadership
Leadership

There should be no need to create another cluster.

You mentioned that you have two hosts, one with a Westmere CPU, and one with a Nehalem CPU.

So what you may do is to vMotion all VMs that have not been powered on on the newer Westmere host to the Nehalem host. That's basically all VMs for which vCenter Server allows the migration. Then shut down the remaining VMs on the Westmere host. After that you should be able to enable EVC for the "Nehalem" generation.

If you cannot shut down all the "Westmere" VMs at once, you could shut them down one after the other, do a cold migration to the Nehalem host, and power them on again. Remeber to set DRS to manual (if used) to avoid an automatic placement during power on.

André