Oracle RAC clustering setup

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

This article is a supplement to the VMware Oracle RAC Setup Guide to help you to perform a RAC setup.

Environment

VMware vSphere ESXi

VMware vCenter Server

Resolution

When you set up a clustering solution there are a number of paths you can choose from. The first is the main setup in the guide and should only be used for Oracle clusters, or any cluster running with SCSI 2 reservations instead of SCSI 3 reservations.

Scenario 1: Setting up Oracle RAC using VMDKs

 

1. Create the virtual machine and place the boot disk on its own SCSI controller.
2. Add the various disks which you'll want to share on a separate SCSI controller (1:0 and beyond). These disks should be set to thick provisioned eager zero (or for ESXi/ESX 4.0, select the Support Clustering Features such as Fault Tolerance check box).
3. Set the disk to be independent and click Finish.
4. When the first virtual machine is created, create the other virtual machines that will run in the cluster. However, when adding in the shared disks for the virtual machines, do not create new disks. Add existing disks and select the same disks that were added to the first virtual machine.
5. In the edit settings page, click the SCSI controller 1.
6. Set the SCSI Bus Sharing option to None.
7. Click Change to change the SCSI controller type to VMware Paravirtual.
8. Click OK.
9. Right-click the virtual machine. Click the Options tab.
10. Click General under the Advanced section.
11. Click Configuration Parameters. In the table, add in the SCSI targets for the shared disks and set the value for them to multi-writer. This will disable the default locking that the hosts would normally do to ensure that only one machine can access the files at any time.

 

Scenario 2: Setting up Oracle RAC using RDMs

This setup is similar to the previous scenario, but with RDMs there is less risk of data corruption and the I/O will perform better.

Note: This is the preferred setup as it will eliminate the errors that can occur when using multi-writer with SCSI 2 reservations.

1. Present the RDMs that you want to use with the hosts.
2. Create a virtual machine with a .vmdk boot disk on its own controller (0:0).
3. Add the RDMs on a separate SCSI controller (1:0 and beyond).
4. Set the SCSI controller to VMware Paravirtualized and set the SCSI BUS sharing policy to Physical.
5. When all the disks are added to the virtual machine, you can create the new virtual machines, pointing the shared hard drives to existing Hard Disks and then pointing them at the RDM pointer file which was created during the first virtual machine setup.