SirHaschke
Enthusiast
Enthusiast

Hi,

refering to my older post...EVC Mode .

I have a cluster with 4 vSphere 6.7 ESXI Hosts.

Two with Intel(R) Xeon(R) Gold 6138 CPU @ 2.00GHz Proc. and two with Intel(R) Xeon(R) CPU E5-2699 v3 @ 2.30GHz.

I will enable EVC mode. Which type is the correct one. Is there a Matrix to see that?

A second questions.

This is a productive cluster. If i want to enable EVC mode i must shutdown all my Active VMs or migrate the VMs to other host in another cluster, right?
Is this a possible way:

1. Migrate VMs so that one host is empty in the cluster.

2. Create a new temp. cluster and disconnect the empty host and connect it to the new temp. cluster.

3. Migrate the VMs to the temp cluster

4. Activate EVC in the original cluster

5. Move back the VMs from the temp. cluster to the oroginal cluster

6. Disconnect the temp host and connect it in the original cluster. After that delete the temp. cluster.

Regards

Dennis

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1 Solution

Accepted Solutions
a_p_
Leadership
Leadership

As I've explained in the mentioned discussion, you will have to power off all VMs which have been powered on on the hosts with the newer CPU (i.e. with more CPU features than the older one).

What you can do to keep the downtime as low, you may:

  • create the new cluster with the two older hosts (this should work without the need to power off the VMs on that hosts)
  • evacuate one of the newer hosts (migrating the VMs to the other newer host)
  • add the evacuated host to the cluster
  • power off (one VM after the other) on the remaining host, do a cold migration to a cluster host, and power on the VM again
  • finally (once all VMs have been migrated) add the remaining host to the cluster and distribute the VMs

André

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10 Replies
a_p_
Leadership
Leadership

As I've explained in the mentioned discussion, you will have to power off all VMs which have been powered on on the hosts with the newer CPU (i.e. with more CPU features than the older one).

What you can do to keep the downtime as low, you may:

  • create the new cluster with the two older hosts (this should work without the need to power off the VMs on that hosts)
  • evacuate one of the newer hosts (migrating the VMs to the other newer host)
  • add the evacuated host to the cluster
  • power off (one VM after the other) on the remaining host, do a cold migration to a cluster host, and power on the VM again
  • finally (once all VMs have been migrated) add the remaining host to the cluster and distribute the VMs

André

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the evc-mode you can use is "Broadwell" : https://www.virten.net/2013/04/intel-cpu-evc-matrix/

but you must shutdown all running or suspended vm to enable evc

moving vm to a temporary cluster does not work because the vms are actually running with cpu-features which they do not have afterwards

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a_p_
Leadership
Leadership

... just to clarify

create the new cluster with the two older hosts ...

should be

create the new EVC enabled cluster with the two older hosts ...

André

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SirHaschke
Enthusiast
Enthusiast

I have created a new cluster with enabled EVC mode, see attachment.
Then i try to move the older ESXI hosts zu that cluster.
Error see attachment 1.

Why that?

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i hope there are no running vm on this host? better to put host in maintenance mode before movving.

if that doesnt work try to disable evc, move the host into the cluster and then re-enable evc

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SirHaschke
Enthusiast
Enthusiast

OK, if i disable EVC then it works fine.
But if i try to activate it then error.

I try Haswell mode and this works fine.


Another questions.

If i move an ESXI host to another cluster, is that only possible if there are no VMs hostet?

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sjesse
Leadership
Leadership

This is the way I would do it

1.)Create a Empty cluster with one empty host with EVC turned on.

2.)Migrate VMs that will migrate to the new evc enabled host

3.)When you need more hosts in the new evc cluster, put a host in the non evc cluster in maintence mode and add it to the evc cluster.

4.)When you get to vms you can't move you must turn them off and migrate them

This process is really the best that I've seen, since you cannot get around turning off vms that have a higher cpu level then the evc cluster is set to.

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sorry - seems there is an error in the link i posted above. e5-2699v3 is haswell not broadwell.

you can move a host with running vms to another cluster. but when evc is active and reduces the cpu-commandset of running vms this is not possible.

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sjesse
Leadership
Leadership

Which is basically what the aceepted solutions says as well. The key points are you can't move a vm that has a higher level cpu then the evc cluster is set to, plus I'm pretty sure you need to have the host in maintence mode to add it to the evc cluster. If your trying to get around these two facts, there isn't much you can do.

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SirHaschke
Enthusiast
Enthusiast

Thanks to all for your help.
Actually i'm updating my VMs (HW Version and Tools).
I think with this step i do then a cold migration to the new EVC enabled cluster.
After that i migrated the two newer host to that cluster.

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