New Cluster or existing cluster

[phillbl]

I think i am asking a stupid question here but never mind!

we have 5 new server to install in an ESX enviroment. we have 2 existing servers in a cluster that are to be retired. I am going to add the new servers to the existing cluster then migrate the existing VM's over and retire the 2 older servers. This then leaving us with enough capacity for future growth.

Even though you can migrate to a different cluster, is their any point creating a different cluster unless you wanted to do something different with the resource pools? Im just trying to understand why somebody would suggest creating a new cluster.

Any advice much appreciated.

Thanks

[aldikan]

"Im just trying to understand why somebody would suggest creating a new cluster."

Hi,

It is a good question,

There could be many reasons and justifications for creating new clusters,

For example:

- Segregated by storage type: we have Fiber Channel and NFS ESX clusters

- Sergregated by ESX host hardware: we have 64 bit capable cluster and 32 bit cluster.

- Also new hardware - old hardware clusters is pretty good reason IMHO

Your scenario is fine, you can go either way, remember that if your hardware differs too much especially CPU wise you might not be able to use Vmotion...in the cluster settings

Too migrate if there are problems with Vmotion, use cold migration (Shutting VM down)

Please rate this or other answers if helpful,

Alex

[malaysiavm]

to add to the existing cluster, you need to ensure the CPU compatible for Vmotion, virtual switches and others capcity issues before you doing that. If the environment is compatible, of course combining will improve the HA and DRS among the ESX hosts

Malaysia VMware Communities -

[jpoling]

We were presented with a similar opportunity - four brand new servers. Our environment previously was a four host cluster on which we ran a mixture of production and dev/test VMs. Our consolidation ratio was very high. After researching the old hardware and new hardware, we found that the CPUs would not be compatible for vmotion. So, our best option was to create a new cluster. The new cluster allowed us to put some isolation between our production and dev/test VMs. Moving VMs to the new cluster has been done using cold migrations due to the CPU difference.

that is my experience. ..FWIW

Jeff

[phillbl]

if you do have different processor models etc then i understand the that you are unable to use the vmotion facility of ESX. what if you downed the VM machines & moved them, then powered them up on the new hardware?

will they boot & work ok?

Thanks

Phill

[aldikan]

Hi Phill,

Moved VM should boot and work,

That is what I do in my test lab where I have older cluster with Dell 2650 and newer with 2950.

Just be careful with 64 bit VMs, in my case for example older cluster does not support 64 bit VMs.

Also worth mentioning VMware EVC feature ( Enhanced Vmotion Compatibility). It is a setting on the cluster level:

Right click on the cluster -> edit setting -> VMware EVC ->enable EVC for applicable hosts (Intel or AMD).

I did not use this feature yet, but it should increase chance on successful Vmotions

HTH,

Thanks,

Alex