vSphere Hypervisor

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  • 1.  VMware EVC is enabled only in few virtual machine

    Posted Feb 22, 2024 08:10 PM

    Hi to all!

    I am trying to understand why it is only enabled in a few vm's.
    By the way, VMware EVC is not even enabled at the cluster level. I think it is not even enabled because of processor type issues.

    however I would like to understand why some vm hasVMware EVC enabled?

    can you help me?

    thanks in advance

    2024-02-22_21-06_2.png2024-02-22_21-06_1.png2024-02-22_21-06.png



  • 2.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 23, 2024 12:04 AM

     Sounds like someone has enabled "Per VM" EVC mode on those VMs in the past. Without knowing the history its hard to say why. Maybe they came from another cluster or Standalone host, and someone enabled it to allow those VMs to be migrated to a cluster where EVC was enforced.  If you want to make things consistent, simply turn it off on the affected VMs.

     

    You can do this by selecting the VM > Configure > select VMware EVC > Edit > Disable

     

    Also if you have hosts with different generations of Intel processor, you might want to enable EVC at the cluster level and set it to the oldest Intel CPU type in your cluster. 

     

    HTH



  • 3.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 23, 2024 07:19 AM

    Thanks markey165

    situation is very strange!!

    i know that vm was in other cluster 4,5 years ago but i dont know migration date.

    in the vm of the screenshot, VMware EVC is enable but is not possible to disable.

    Possible that VMware EVC is enabled automatically in vm possible to be trasferred to other cluster node? Vm with less ram and storage? ex 4GB ram and 32GB HD?

    Cluster has not many resource...ram and storage are at the maximun..

    2024-02-23_08-09.png

    2024-02-23_08-17.png



  • 4.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 23, 2024 08:40 AM

    in the vm of the screenshot, VMware EVC is enable but is not possible to disable.

    I don't have my lab in front of me at the moment, but i would guess for a setting like this, the VM would need to be powered off to make the change, as it relates to CPU architecture instructions sets. So very likely can't be changed on a running VM.

     

    To my knowledge, EVC is never enabled automatically, only manually.

     

    HTH

     



  • 5.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 23, 2024 09:13 AM

    hi markey165

    in some vmachine, there aren't VMware EVC item in configure menu!

    cestello67_1-1708679587745.png

     



  • 6.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 23, 2024 09:36 AM

    Its just a guess, but is it possible it isn't appearing on those VMs because 1) they are running, and 2) don't have EVC mode enabled?

     

     



  • 7.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 24, 2024 02:13 PM

    i've made a test:
    i've poweroff a vm which has VMware EVC enabled.

    When vm was off, in Configure / VMware EVC : VMware EVC was DISABLED

    When i power on vm, in Configure, setting VMware EVC appear Enabled



  • 8.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 23, 2024 02:00 PM

    It no about EVC being enabled. At the time a VM in a non EVC enabled cluster is powered on, it will receive the host's CPU features.
    The CPU feature for these VMs don't match the EVC mode, which could be causes by different hosts (CPUs) in you cluser, and the VM has been powered on on the newer host, or that you have Skylake CPUs and the VM has not been power-cycled for a long time (see https://kb.vmware.com/s/article/76155 for details)

    André



  • 9.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 24, 2024 02:14 PM

    i've checked all vm and a common feature for all that appear with VMware EVC is Enabled was that have hardware versione => 14



  • 10.  RE: VMware EVC is enabled only in few virtual machine

    Posted Feb 24, 2024 04:03 PM

    OK, i've done other research and i have found that hardware version needed for EVC is 14...

    https://kb.vmware.com/s/article/91903

    and in my cluster was not possible to enable EVC because in a host there are 2 vm with no virtualization enabled in CPU options!