Connect and configure the disk drive enclosure in a system with the Linux operating system

Use the information in this section to understand the cabling, SCSI addressing, and post connection requirements for the disk-drive enclosure.

Install the initiator repeater cards into the disk drive enclosure. For instructions, see SCSI repeater card.
Connect the SCSI cable to your repeater card. Choose one of the following based on your situation:
- If you are using only single repeater cards or only dual repeater cards, install your SCSI cable A to the initiator repeater card B. For more details, see Figure 1, Figure 2, Figure 3, depending upon your situation.
  Figure 1. SCSI cable to single repeater card
  
  Figure 2. SCSI cable to dual repeater card connected with two SCSI cards
  
  Figure 3. SCSI cable to dual repeater card connected with four SCSI cards
- If you are using a combination of single and dual repeater cards, install a SCSI cable to the dual initiator repeater card A. Then, connect the dual repeater card A to the single repeater card B with a different SCSI cable. For more information, see Figure 4.
Figure 4. SCSI cable to dual repeater card connected to single repeater card
Install the other end of the SCSI cable C to the SCSI adapter D on the server. For more details, see Figure 5.
Important: The SCSI adapter or the system or partition must be powered off before making this connection.

Figure 5. SCSI cable to SCSI interface card
Add the disk drives to the operating system you are using, see Rebuild data on a replacement disk drive using Linux for instructions on how to configure those disk drives.
Important: If you plan on using the disk enclosure in a Linux® environment, it is critical that you set up a Linux CRON job so that if errors exist, they report to the attached system. The Linux CRON job needs to be setup during the initial install.
Set up the Linux CRON job during the initial install of your SCSI disk-drive enclosure. Perform the following tasks to ensure that your Linux CRON job is setup.
1. Install the following RPMs from Service and productivity tools (http://www14.software.ibm.com/webapp/set2/sas/f/lopdiags/home.html).
  - librtas
  - lsvpd
  - ppc64-utils
  - diagela
2. If your partitions are managed by a Hardware Management Console (HMC), install the src, rsct.core.utils, rsct.core, csm.core, csm.client, and devices.chrp.base.ServiceRM packages in order to report errors to the Service Focal Point on the attached HMC. Instructions for installing the packages are located on the previous Web site.
  Note: Errors on hard disks within the enclosure will not be found using this CRON job. This diagnostic is limited to reporting errors with the fans, power supplies, VPD card, and repeater in the enclosure.
3. Add a CRON job to execute enclosure diagnostics to the system CRON table. As root, edit the system CRON by running crontab -e. At the bottom of that file, enter:
  * 3 * * * /usr/sbin/diag_encl -s 1>/dev/null 2>&1
4. Adding this line causes the diagnostic application /usr/sbin/diag_encl to be run daily at 3:00 a.m. The diag_encl diagnostic application will read the contents of the /etc/diagela/diagela.config file to determine what applications have been registered to be notified of errors. To add additional notification methods or for more information, see that file. By default, the following notifications will occur.
  - The Service Focal Point on the HMC will be notified if the system is managed by an HMC. If the system is not managed by an HMC, the root group will be notified.
  - If the system has Electronic Service Agent™ installed, it will be notified.
  - The error details will be printed to the console, to the end of the /var/log/platform log file, and to the syslog (/var/log/messages).
    Notes:
    - On a partitioned system, it is only necessary to have the CRON job on one partition associated with the enclosure. However, it is acceptable to have the same CRON job on all partitions.
    - /usr/sbin/diag_encl might run at any time to diagnose enclosures attached to the system.