If you are not using that, then you are fine, otherwise, you have to use a modified fencing agent that is vi aware, and can kill nodes through the vi api and vCenter instead of directly from the host.

-KjB

Create the virtual machines.

Create a passthrough RDM using vmkfstools, for the cluster nodes.

Once the RDM file is created, add it to the cluster node machines.

Verify LUN mapping from the virtual machines.

So, after the LUN mapping, get the cluster created, and get your cluster multicast IP.

The multicast is where things get hung up. In a Cisco environment, it was almost impossible to let Cisco devices figure things out on their own. So, create a static entry for each port on the switch that will be part of the multicast group. This method was easier than trying to setup a multicast router, and was more localized to the cluster at hand. The one thing to watch out, is that if you have switches in a redundant fashion, then you have to make sure to include the ports that connect the switches (whether they be trunk/ISL/port channeled). Otherwise, all cluster nodes will not be able to recognize each other, and you'll have mixed results when trying to query your cluster vote.

Once that issue is resolved, it's on to fencing. Fencing has been interesting as well. From what I've seen, the RHEL fencing agents for vmware, treat ESX as stand-alone entities, and hadn't yet been updated to talk to VI. This appears to be changing, and there are solutions on the net that allow for the vi perl toolkit to be utilized to "shoot vm's in the head" in case of errors. This is relatively new, and gets us away from using customized fencing agents, which, of course, are not officially supported by RedHat.

-KjB

Thanks for all your help.

One restriction I have noticed in some documentation is that using an RDM volume in physical mode will not work with HA. This could be a problem for me.

I have 2 ESX servers and 1 ESXi server. There are 3 VMs that need to see the shared disk with GFS on it, 2 web servers and a file management server. The file management server processes data (images mainly) and puts it on the storageso that the web serverscan then serve it up to web clients.

ESX1 gets "web1"

ESX2 gets "filemgmt"

ESXi gets "web2"

I don't mind if either of the web servers goes down and does not come back with HA, but there is only one file management server and it needs to auto-restart using HA if the ESX host it is on goesdown. It needs to be able to see the GFS volume from its original or alternate ESX server.

If mounting the GFS volume via RDM will tie filemgmt to one phyiscal server (which I need to avoid), could I consider running an iSCSI iniator within the VM to mount the GFS volume instead? If this isfeasible, are there any caveats I need to know about?

Many thanks for your help on this.

Michael