Adding a standalone ESX3.5 host (with running guests) into a cluster.

[csherwood]

Good Day fellow VMWare'ers:

I'm just wondering if someone had tried this before. Basically I have an ESX 3.5 u2 server as a standalone server, and a 3 node ESX cluster. All machines (clusterred and non-clusterrred) are exactly the same hardware, and connected to the VLANs in the same way. The only thing that they standalone machine doesnt have currently is an attachment to the shared storage, but thats just a minor formality.

What I'm hoping to do is add the standalone server into the cluster (after ensuring that the networking setup, etc is identical) and then use storage vmotion to get the hosts onto the shared storage, and off local storage.

The catch is that I'm hoping to accomplish this while the guests on the standalone ESX server are running (ie: zero downtime).

Thanks in advance for all the input received. Cheers!

[Sanjana]

Hello csherwood,

Welcome to the forums. While I haven't tried out this specific scenario, what you described sounds pretty straightforward and should work. Take a look at this thread for a similar discussion.

AFAIK, as of update3, the requirements for storage vmotion state that the source ESX host should be able to see both the source and destination scsi targets. You can find the complete set of requirements and limitations for storage vmotion at this kb article.

--sanjana

[craigal]

I have on a number of occasions, added an ESX host to an existing cluster while VMs were running on that host.

This had no affect on the VMs

Craig

[csherwood]

I accomplished this, but with a few caveats. One was that I had to disavle Enhanced vMotion Compatibility (EVC) in order to add the machine to the cluster. The alternate option (which I didnt go for) was to shut the standalone machine now, add it to the cluster and then turn it on.

Once I had the server added to the cluster, SVMotion and VMotion worked like a charm. The only thing I had to do was since I disabled EVC on the cluster, I had to shut down ALL the VMs in the cluster in order to turn EVC back on.

Again, thanks for the help!