Short tutorial: ESX 3.0 cluster in-a-box with RDM

Hi guys,I decided to write a small tutorial on clustering (in a box) with RDM on ESX 3.0.
What you need:

• 1 ESX 3 server
• 2 virtual nodes with the same config:
  • 2 virtual NICs, 1 to an external switch, 1 to an internal switch with no external pNICs
  • min. 2 virtual hard drives, on a separate virtual LSI Logic SCSI controller
• A small LUN to use as the Quorum disk (100 Mb)

Each VM node should be configured with a separate LSI logic controller, 2 extra Hard disks (pointing to a Raw LUN, quorum and resource) and an extra “heartbeat” NIC. The SCSI controller should be set to “Virtual” when using a cluster-in-a-box (on 1 ESX server).

The extra harddisks are mapped directly to a SAN/iSCSI LUN via RDM in virtual compatibility mode (non‐pass‐through RDM).

For the first node, use the add hardware wizard to add the extra disk and select “Mapped SAN LUN” to make a .vmdk disk that points directly to the RAW LUN (instead off a new/existing .vmdk disk on a VMFS datastore).

On the compatibility mode, select “Virtual”.

Make sure that you choose SCSI (1:0) and NOT (0:0)!

For the second node, follow the same procedure, but choose “Use an existing virtual disk” and point it to the .vmdk file created for the other node (should be something like “[iscsilun4-DS] Sr-Node1/Sr-Node1_1.vmdk”). Use the exact same config (SCSI (1:0) for the quorum disk, etc.).

That’s about it! The rest of the configuration is a default cluster setup.

For extra info, consult this PDF on clustering