Windows 2008 Cluster Testing on the Cheap

I'm successfully testing Windows 2008 Clustering without expensive SAN storage.  Not everyone has extra servers and a SAN to play with.  What I did have was an HP BL460C blade server with internal SAS hard disks and a free copy of VMWare ESXi 4.1. 

After installing ESX, I built two Windows Server 2008 R2 Enterprise Edition VM's.  To create the shared storage, I simply created a shared disk in VMware.  To do this, launch the vSphere client, connect to your ESX server (or vCenter server if you have one), navigate to the first 2008 VM, right-click and Edit Settings.

Click Add, select Hard Disk and select "Create a new Virtual Disk".  Next, select the size of the disk, and select the "support clustering features" checkbox as shown in figure 4.  That allows two VMs to access the same disk without an exclusive lock.  Next, choose a virtual device node (a virtual LUN ID).  Shared disks can not be on SCSI adapter 0 under VMware, so select 1:0.  This will automatically create a second virtual SCSI adapter.

Figure 4 - Adding a clusterable VM disk

After creating the new disk, you will see a new SCSI adapter in the hardware list of the VM.  Select this new SCSI adapter, and set the SCSI Bus Sharing mode to Virtual.

OK, node 1 of our cluster can see the new disk.  Now let's add it to our second node.  Navigate to the other 2008 VM, and edit settings.  Add a hard disk, this time select existing disk.  Browse to the new disk (stored in the first 2008 VM's folder) and add it.  Again, select SCSI 1:0 and change the new SCSI adapter's sharing mode to virtual.  Done!  Now you can cluster the 2008 VM's using your shared virtual disk.

There you go, Windows 2008 Cluster testing on the cheap!  Happy testing.