5GB 8mm Tape Drive Install Problem

A problem has been discovered when a system is booted with an 8mm 5GB tape drive (7208-011 and feature codes 6144, 6147, 6148, 6149; also generic Exabyte 5GB tape drives). This problem exists both with the IBM version and generic Exabyte version 5GB tape drives. There is an incompatability between the microcode on this tape drive and the microcode on some RS/6000 SCSI controllers. This problem only occurs during a boot from this tape drive; and even then it will only occur if attached to certain levels of the SCSI controller.

The symptom is that the system will appear to boot successfully but will have file corruption. Some corruption can be detected as check sum errors, some may be detected as operational errors, and some may not be detectable at all.

If you have ever installed from an AIX software distribution tape or from a mksysb tape using the 8MM 5GB tape drive, it is possible that files have been corrupted. Only files that are in rootvg could be corrupted. Therefore, if you have your applications or application data in rootvg, it could possibly be corrupted. In this case, you will need to take action to correct and to prevent any additional file corruption.

If you have an 8mm 5GB tape drive and you are using it for boot purposes, check the SCSI controller to which the tape drive is attached. You can do this by executing the AIX command "lscfg -v | pg" and then viewing the results on the display screen. Press Enter to page down and press the minus key and Enter to page up. Look for the part number for the embedded controllers under the heading "sio0"; look for the part number of the SCSI adapter cards under the heading "scsiX" where X is any number.

If your controller is listed below, then please order the proper Engineering Change Announcement (ECA) from your hardware service organization.

If you use the tape drive on multiple systems, you would want to order the proper ECA for any card/planar to which you are likely to attach the tape drive. If you apply the ECA to an embedded controller, that ECA will cause the boot to perform properly from any adapter used in that machine.

If the SCSI controller you are using is not on the list above, you should not have this problem.

Note 1: The fix for the embedded controllers is a two-part fix. One part is the hardware included in the ECA. The other part is that if you are not comfortable with editing the files, contact your AIX support center.

The IPL ROS includes part of the fix for the problem. The VPD and new labels are for record-keeping (so this machine will be distinguishable from one that hasn't been updated). The diskettes are install diskettes for booting up without exposure to data corruption (they contain downloadable SCSI controller microcode which fixes the problem).

1. Replace the VPD module, IPL ROS, and labels on the CPU Planar. For details on the installation procedure, refer to the instructions included with the parts.

   Note: With the new VPD, the CPU ID of your machine will change. This may cause problems with certain software applications which rely on a certain CPU ID to operate. If this is the case, the applications will have to be updated somehow. If this is not possible or desirable at this time, you may postpone replacing the VPD. The machine will still operate with the old VPD.

2. Here are the rules for determining potential data corruption:
   • If you have never installed or restored from a mksysb using a 5 GB tape, you will have no data corruption.
   • If you have installed or restored from a mksysb using a 5 GB tape, some of your files may be corrupted:
     • System files may be corrupted in either case.
     • Application files may be corrupted only if they meet two conditions: they reside in rootvg, and they were restored from a mksysb tape. If either of these conditions is not met, the application files will not be corrupted.
3. If you meet any of the conditions for potential corruption, you will need to reinstall the system. Boot from the included install diskettes using the standard BOSboot diskette procedure. At the appropriate prompt, select the option to install AIX from the tape and use your original AIX tape. Additionally, if any of your applications have been exposed to corruption, you will need to reinstall them as well.

   Note that, even if you have not seen the problem, you should apply the hardware fixes and the following software fixes to avoid seeing the problem in the future.

4. After the system has been reinstalled, edit the files:
   1. /usr/lib/boot/tape.proto
      1. Search for the string: 8d77
      2. Add two lines

         FROM

          
            microcode d--- 777 0 0 
                  8d77.32.04  ---- 777 0 0 /etc/microcode/8d77.32.04 
                  $ 
         

         TO

          
            microcode d--- 777 0 0 
                  8d77.32.04  ---- 777 0 0 /etc/microcode/8d77.32.04 
                  8d77.44.54  ---- 777 0 0 /etc/microcode/8d77.44.54 
                  8d77.42.54  l--- 777 0 0 /etc/microcode/8d77.44.54 
                  $ 
         

         Note the lower-case "L" on the third line.

   2. /sbin/rc.boot
      1. Search for the string: Tape
      2. Add one line (a few lines down from Tape)

         FROM

          
            showled 0x510 
            # Run config manager for phase 1 boot 
            /etc/cfgmgr -f 
              showled 0x511 
         

         TO

          
            showled 0x510 
            #Run config manager for phase 1 boot 
            /etc/cfgmgr -f 
            /etc/cfgmgr -s > /dev/null 2>&1 
            showled 0x511 
         

5. Affix the label to your AIX install tape. This will ensure that in the future, if another system is installed with this tape, that the new diskettes will be used, thus preventing any data corruption on install.
6. If you have had any problems with this procedure or have any further questions, contact your AIX support center.