Dell 4200 manual Scsi Host Adapter IDs, Disabling a RAID Controller Bios

This warning alerts you to the possibility of data loss if certain precautions are not taken to protect the integrity of the data on your cluster. To prevent the loss of data, be sure that your cluster meets the following conditions before you attempt any data-destructive operation on your shared hard-disk drives:

•Be sure the peer server is powered up during the operation so that its RAID controller nonvolatile ran- dom-access memory (NVRAM) can be updated with the new configuration information. Alternately, if the peer server is down, you must save the disk configu- ration to the shared storage subsystem. When you restart the system later, update the peer server’s NVRAM from the disk configuration saved to the shared storage subsystem.

•Be sure the peer cluster node is not currently config- uring the shared storage subsystem.

•Be sure that no input/output (I/O) activity occurs on the shared storage subsystem during the operation.

SCSI Host Adapter IDs

On a small computer system interface (SCSI) bus, each device must have a unique SCSI identification (ID) num- ber. The default SCSI ID of the RAID controller is 7. However, with RAID controllers from two cluster nodes occupying the same bus, the controller in the second clus- ter node must be set to a different SCSI ID to avoid a device conflict. Therefore, the RAID controller in the second cluster node should be set to SCSI ID 10. In addi- tion, because multiple RAID controllers can reside on each node, all RAID controllers on the second node must be set specifically to SCSI ID 10.

Use the RAID controller BIOS configuration utility to set a SCSI ID. Start the utility by pressing <Ctrl><m> during the system’s POST. From the Management Menu, select Objects, then select Adapter, then select the appropriate adapter (if applicable), and then select Initiator ID. If you are running the utility from the first cluster node, the SCSI ID should be set to 7. If you are on the second clus- ter node, change the 7 to 10 and press <Enter>. At the confirmation prompt, select Yes and then reboot the clus- ter node by pressing <Ctrl><Alt><Delete>.

Disabling a RAID Controller BIOS

The BIOS for all of the cluster-specific RAID controllers must be disabled. Only a RAID controller that is control- ling the system boot device should have its BIOS enabled.

Use the RAID controller BIOS configuration utility to disable a cluster RAID. Start the utility by pressing <Ctrl><m> during POST. From the Management Menu, select Objects, then select Adapter, then select the appro- priate adapter (if applicable), and then select Disable BIOS. Select the Disable BIOS setting if it is listed. If Enable BIOS is the choice that is offered, the BIOS for the RAID controller is already disabled.

RAID Level for the Shared Storage Subsystem(s)

The RAID level can be set using the RAID controller BIOS configuration utility. Start the utility by pressing <Ctrl><m> during POST. The recommended default RAID level for a cluster with two Dell PowerEdge Scal- able Disk System 100 (SDS 100) storage systems is RAID 1+0. RAID 1+0 is a combination of RAID levels 1 and 0. Data is striped across the SDS 100 drives as in RAID 0. Each drive is mirrored on the second SDS 100, as in RAID 1. RAID 1+0 allows high-availability of the quorum resource, which can be mirrored on hard-disk drives on both SDS 100 systems.

For cluster systems with a single SDS 100 storage sys- tem, the recommended configuration consists of two logical drives—two of the SDS 100’s hard-disk drives comprising the first logical drive and the remaining drives (up to six) comprising the second logical drive. The first logical drive should be configured for RAID 1 (disk mirroring) and should contain the quorum resource. The second logical drive should be configured for RAID 5 and should contain application data for the cluster.

RAID Level for the Internal Hard-Disk Drives (Optional)

Like the RAID level for the shared storage subsystem, this configuration can also be set using the RAID control- ler configuration utility. The recommended default configuration of the internal drives is a RAID 5. Addi- tionally, the default channel for connecting the controller to the internal drives is channel zero.

3-2 Dell PowerEdge Cluster (PowerEdge 4200) Installation and Troubleshooting Guide