K380 Disappearing DVD or Disk Drive.

[Brian Rich_1]

I have successfully loaded hp-ux 10.20 onto one k380. There are three drives in the system, one 9GB (system disk), and two 18GB data drives. Once the system is booted up and I view the drives through SAM, one of the drives has shown up as having 0MB. The DVD drive is there sometimes but not others. And lastly, in a separate machine, the 9GB drive has disappeared and everything else shows up. I am totally lost (which is nothing new if you read my other posts). Any help would be greatly appreciated!!

[Brian Rich_1]

I forgot to mention that I have made sure that they all devices have a different scsi id set and been seated properly.

[Jeff Schussele]

Hi Brian,

Sure sounds like a SCSI subsystem problem of *some* sort. Make sure termination is proper & *only* at the ends of the chains. You may also want to try a different SCIS cable.

Rgds,
Jeff

[A. Clay Stephenson]

Poor termination can cause exactly this sort of problem. Things will almost work perfectly.
1) Make sure that you have the correct type of terminator. For example, a SE-SCSI terminator can physically plug onto a FWD/HVD SCSI connector. The connectors are the same but the terminators, along with are other devices, must be wither all SE-SCSI or all HVD SCSI.
2) Make sure that you have exactly two terminators on the physical ends of each bus. Often the terminators are built into the controllers. Make sure that the resistor packs are inserted (if this applies to your controller).
3) At least one device per bus must supply power for termination.
4) Do not exceed the maximum bus length applicable to your SCSI topology.

The "here now, gone again" scenario is very typical of poor termination.

[Brian Rich_1]

If I am understanding you two correctly the cables themselves should have terminators on the end of them. I have checked all of the cables and both the Narrow DVD cable and the FWD cable has termination. The weird part about this is that the system saw everything when only the first and third drive were connected but when the second drive was connected the DVD and Tape drive would disappear. We unplug the middle drive again and again it sees the DVD. Could it have anything to do with the type of drives that we are using? We are using both 9GB WC/WD and 18GB WC/WD seagate drives with a converter attached on the ends. I have attached a pic of the back of the disk tray.

[A. Clay Stephenson]

It's a little difficult to follow all of this but you should note that the DVD (I assume that it is replacing the CD-ROM) should be on the SE-SCSI bus. Nothing on that bus should have any effect upon the FWD bus. Because you have indicated that the cables have terminators on them, it is now necessary to make certain that none of the drives are terminated. Also, if not external devices are connected to the FWD bus (this bus has an unterminated controller in the middle with one end going to the internal FWD bay and the other end is an external connector) then you must install a FWD terminator on this connector. It soulds as though youy may be trying to install a SE/LVD SCSI device on the FWD bus OR you are putting a terminated device in the middle of an already terminated bus. It is perfectly legal to terminate on the last device on a bus provided that the bus ends in a simple plug rather than a terminator. Finally, the integral terminators on the cables have been known to fail.

Some ioscan -fn's posted showing your various problems might be helpful.

[Brian Rich_1]

Thanks for all of the help! I still have not solved the problem but i have taken everything out except one 9GB drive, the dvd, and the tape drive. No matter what machine i put the drive bay in, it comes up with the attached warnings and error messages. I get these messages with two different machines, two different drives, and two different dvd's. At first i thought it was drive related but even with different drives i get the same message. If anyone has any insight, lunch is on me.

[A. Clay Stephenson]

Well, that attached posting wasn't very helpful. Interrupt the boot process and enter SEA to SEARCH for devices.

[Brian Rich_1]

Here is the rest. I did not post it b/c it shows that nothing is being seen.

[A. Clay Stephenson]

I have a feeling that you have exploded your controller by putting incompatible components on a bus. NOTHING except HVD devices should ever be attached to an HVD SCSI bus. At this point I would pull everything off the SE-SCSI bus (tape and dvd) and the only device on the HWD/BUS should be a known HVD drive. Make sure that the external connector is terminated. If the SEA fails then you definitely have bad hardware.