Installing an HA single-system RAID configuration

Use this procedure to help you to install an HA single-system RAID configuration.

1. Install and update the iprutils package on each system or partition. See Updating the iprutils package for more information.
2. Power off the system or partition and install the SAS controllers into the system or partition. If you do not want to power off the machine or partition, Linux hot plug can be used to install the SAS controllers without powering off the system or partition.
   Attention: Do not attach any cables to the SAS controllers at this time.
3. Update each controller to the latest SAS controller microcode from the code download Web site. See Updating the controller microcode.
4. To prevent errors while connecting the cables, configure the SAS controllers to the HA single-system RAID configuration before attaching any cables to the SAS controllers:
   1. Run iprconfig
   2. Type 7 to select Work with adapter configuration.
   3. Use the up/down arrow keys to move the cursor to the SAS controller and type 1; then press Enter to select it.
   4. In the menu option titled Change Configuration of Adapter, configure Preferred Dual Adapter State to None and High-Availability Mode to RAID.
5. Attach an X cable from the shared disk expansion drawer to the same SAS connector on each controller. To see examples of how to cable the HA configurations, see Serial attached SCSI cable planning. For examples of how to cable the HA configurations, see ″Two SAS adapters to disk expansion drawer – RAID.″
6. Power on the system or partition if it was powered off. Verify that the cabling and functioning of the controllers are correct by using the Display Hardware Status screen. Each SAS controller in dual-initiator configuration should show an optional block of Remote Adapter information for the other SAS controller.
   1. Run iprconfig
   2. Type 1 to select Display Hardware Status.
   3. Use the up/down arrow keys to move the cursor to the SAS controller and type 1; then press Enter to select it. An optional block of Remote Adapter information for the other SAS controller in the remote system or partition is shown in the bottom of the IOA Hardware Resource Information Details screen, similar to the following:

      +------------------------------------------------------------------------------+
      |                    IOA Hardware Resource Information Details                 |
      |                                                                              |
      |                                                                              |
      |Manufacturer . . . . . . . . . . . . . . : IBM                                |
      |Machine Type and Model . . . . . . . . . : 572B001SISIOA                      |
      |Firmware Version . . . . . . . . . . . . : 03200046                           |
      |Serial Number. . . . . . . . . . . . . . : 07125793                           |
      |Part Number. . . . . . . . . . . . . . . : 0000042R4591                       |
      |Plant of Manufacturer. . . . . . . . . . : 0022                               |
      |Cache Size . . . . . . . . . . . . . . . : 175 MB                             |
      |DRAM Size. . . . . . . . . . . . . . . . : 0EE MB                             |
      |Resource Name. . . . . . . . . . . . . . : /dev/sg20                          |
      |                                                                              |
      |Physical location                                                             |
      |PCI Address. . . . . . . . . . . . . . . : 0002:00:01.0                       |
      |SCSI Host Number . . . . . . . . . . . . : 1                                  |
      |                                                                              |
      |Current Dual Adapter State . . . . . . . : Primary                            |
      |Preferred Dual Adapter State . . . . . . : No Preference                      |
      |Remote Adapter Manufacturer. . . . . . . : IBM                                |
      |Remote Adapter Machine Type And Model. . : 572B001SISIOA                      |
      |Remote Adapter Serial Number . . . . . . : 07125687                           |
      |                                                                              |
      |Current Asymmetric Access State. . . . . : Disabled                           |
      |                                                                              |
      |                                                                              |
      |Press Enter to Continue                                                       |
      |                                                                              |
      |e=Exit   q=Cancel                                                             |
      +------------------------------------------------------------------------------+

7. Optional: Configure one of the controllers in the HA single-system RAID configuration to be the Preferred Primary controller by following the steps below:
   Note: Such configuration is often done for performance and usability reasons, such as disk configuration changes. If neither controller is configured as the Preferred Primary controller, the controllers will default to primary or secondary through a negotiation process during boot.
   1. Run iprconfig
   2. Type 7 to select Work with adapter configuration.
   3. Use the up/down arrow keys to move the cursor to the SAS controller and type 1; then press Enter to select it.
   4. In the menu option titled Change Configuration of Adapter, configure Preferred Dual Adapter State to Primary.
   When determining the Preferred Primary controller, consider the following:

   • Because all disk array access must go through the primary controller, performance will be better for disk I/O operations from the system or partition containing the primary controller.
   • All disk array configuration changes must be done on the system or partition containing the primary controller.
   • Most disk service, including error log analysis, is performed from the system or partition containing the primary controller. However, errors might also be presented by the secondary controller that might require actions on the system or partition containing the secondary controller.