JonRoderick
Hot Shot
Hot Shot

Why can't I enable EVC on my brand new identical hosts?

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I've tried to enable EVC on my cluster of IBM 3650s with dual quad-core E5440s but VC won't let me.

Any ideas why? I know the Intel Flex-migration feature set is a requirement but do I need to enable that in the BIOS or something?

I notice in the admin guide the follow Intel processors are supported:

Baseline - Intel Core 2 (Merom), with specific processors Intel Core 2 (Merom) and Intel 45nm Core 2 (Penryn) - does this mean my E5440s (Harpertown) aren't supported? After reading a bit about flexmigration - I have a nasty feeling it's only supported in the 7300 series chips so far.

Cheers.

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christiandouma
Enthusiast
Enthusiast

Try to see in the bios if VT (virtualization) and the No execute bit is enabled. I had problems with our HP DL580g5 and in the end I fixed EVC by enabling the No Execute processor option in the bios.

View solution in original post

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stvkpln
Virtuoso
Virtuoso

For whatever reason, EVC can only be enabled in one of the following two scenarios (assuming hardware is supported!!): 1) a brand new cluster with no hosts/VM's; or... 2) an existing cluster where all of the VM's are powered off. I know, it makes no sense, but that's what they did.. So if you have new gear you want to add into the mix, you can setup a new cluster and begin vmotioning VM's over from one cluster to the other (this is doable), then slowly move your hosts from the old cluster to the new. Not the most optimal of solutions, but it is what it is.

-Steve
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JonRoderick
Hot Shot
Hot Shot

Nah, this is a brand new cluster, 2 hosts, no VMs - just trying to enable it....do you know which chipsets support flexmigration (my E5440s)?

Thanks.

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depping
Leadership
Leadership

Well it makes sense in a way. EVC uses a sort of CPU masking which changes the way the cpu is exposed to the vm, you can't change the cpu of a running machine.

Duncan

My virtualisation blog:

If you find this information useful, please award points for "correct" or "helpful".

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JonRoderick
Hot Shot
Hot Shot

Hmm, sorry, I don't think this is involves VMs - I am sure this is to do with the chipsets - can anyone confirm which chipsets are supported by EVC?

The error I get is:

EVC cannot be enabled because one or more hosts in the cluster do not support EVC.

An obvious message I grant you but I need complete clarification that the reason they don't support it is because of the chipset I'm running.

Cheers.

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stvkpln
Virtuoso
Virtuoso

According to this Intel Compatibility Matrix (http://tinyurl.com/6rnper), your processors should be supported. VT needs to be enabled in the BIOS on the server, but you'll want to confirm with IBM themselves that they have a rev of BIOS that has support for FlexMigration. That's about as deep an understanding as I have at it from the Intel side.. our infrastructure is almost exclusively AMD-based today.

-Steve
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stvkpln
Virtuoso
Virtuoso

Duncan, I don't disagree, per se... However, if you have an existing cluster... all of your hardware should already be static and compatible if you're making use of vmotion and such... So, why wouldn't EVC just be a checkbox or radial I select and turn on? Everything should already be compatible, and anything new that gets added will taken on the entity of the existing EVC setting. Mostly, I take issue with the fact that I have to go through that much work just to enable a feature that's supposed to reduce my overall headache of hardware management and lifecycling.. Going through the process may not be such a big deal in a smaller environment, but in larger environments, not so much.. But, the product manager for EVC has already heard my opinion (rather vigorously, even) on the subject, so who knows.

-Steve
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JonRoderick
Hot Shot
Hot Shot

Thanks - certainly looks as though the E5440s should support flexmigration - I'll take this up with IBM.

Cheers.

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christiandouma
Enthusiast
Enthusiast

Try to see in the bios if VT (virtualization) and the No execute bit is enabled. I had problems with our HP DL580g5 and in the end I fixed EVC by enabling the No Execute processor option in the bios.

View solution in original post

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JonRoderick
Hot Shot
Hot Shot

Thanks - I know VT is enabled but I suspect No-Execute isn't - doesn't mention this in any documention I've read no in the support call I've got open but I've asked for someone to test it out and I'll post back with results. Thanks Christian.

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JonRoderick
Hot Shot
Hot Shot

Christian, you are the man - enabling the execute disable bit now allows the host to take part in EVC - why, oh why was it so difficult to find this out and why didn't IBM/VMware just know this straightaway? Ah well....thanks - points all yours.

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bertdb
Virtuoso
Virtuoso

That's exactly what I did to enable EVC on my test cluster. I have just two hosts, in one cluster, with VirtualCenter in a VM. So shutting down all VMs just isn't an option for this cluster, as it would include shutting down VirtualCenter. I blogged about my workaround here:

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sam2003
Contributor
Contributor

i tried that method but i cannot migrate the VMs back into the EVM enabled cluster unless i power off the VMs first. i tried the following steps (it's a two node cluster):

place host1 into maintenance mode, which migrated its VMs to the other host in the cluster, no problem.

drag that host out of the cluster, up to the datacenter level and take it out of maintenance mode, no problem.

drag all the VMs out of the cluster and onto that host, no problem.

enable EVM, no problem there.

now, when i try to drag a VM back into the cluster, it tells me that's not allowed because of that CPUID mismatch. i can drag a VM into the cluster if i power it off first but not while it's powered up.

i tried this with and without HA/DRS enabled. tried rebooting the hosts, rebooting the Virtual Center server (it's a hardware server, not a VM).

can't see what i missed in your procedure.

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kimono
Expert
Expert

Frustrating!

/kimono/

/kimono/
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grog
Contributor
Contributor

It is very frustrating when you have a cluster that is already configured for EVC and then you have to rebuild the cluster for any reason. In my case I have to reinstall VC from scratch on a new DB and I am not restoring the old DB. I know that the EVC base config has already been set and I do not need to power down all of my vms. They were already in an EVC cluster with the same hosts they are going back in with.

The way I got around this:

1. Build 2 clusters in new VC

2. Import and put all hosts in the new non-EVC cluster

3. Use the following script to vmotion from one host to another --- get-vmhost SourceESXhostname | get-vm | move-vm (get-vmhost DestinationESXhostname)

4. Once host is flushed put it in the EVC cluster

5. Use step 3 to vmotion the vms into the EVC cluster

6. Continue this process until all vms and hosts are in the EVC cluster

When you think about it why not ask a question when you try to enable EVC to ask if you are rebuilding an environment. I now have to follow this process for 700+ vms and 40 hosts....

Hope this helps...

Thanks,

Marc

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