Something for MPE at Apple's App Store
Terminal emulation app tested via LinkedIn

Replacing LDEV 1 drives: many options

Our bulletproof Series 918 has finally crashed. It's been a great, solid, stable runner for years. However, I desperately need to find a new, used or refurbished drive to replace its system disk, preferably here in the UK. I assume it was LDEV 1, as it couldn't boot. However, I have two drives in the system drive enclosure, and am not sure how to tell which was designated as LDEV 1.

I figure a like-for-like replacement would be less hassle if I can find one. What I need is a C2490-69365 drive with a massive 2GB of storage, one that has a 50 pin connector.

Craig Lalley answered, with a short method on how to discover which drive is designated as LDEV 1.

Look at the primary boot path.  Then find the SCSI drive with that ID. Disconnect the drive and see if the boot behavior changes.

Keven Miller also replied, with advice about finding drives seemingly everywhere -- and another method to figure which drive is LDEV 1 in a 3000.

I'd prefer to replace that 2GB with a larger one. A 4GB, if you’re running MPE 5.0 through MPE 7.0, and something larger if running MPE 7.5, where you can access beyond the 4GB limit.  I have a 4GB LDEV 1 that houses MPE 6.0, and an 18GB LDEV 2 that’s a user volume for other data. For compatible disks, I have many of have these lying around. I could supply any of the following on my list below, for the cost of shipping only.

Miller's list below came with instructions on making some drives work.

From what I've experienced, any SCSI disk should work. I got an IBM 4GB drive from someplace, and it wouldn’t work. I put it onto a Unix box (HP-UX, Linux I don't recall) then found that the low level format was a 514 block size, not 512. I had to learn about using "setblock" to reformat the drive. Then, I could install MPE onto it as an LDEV 1.

I have these disks laying around

4GB Seagate ST14207W FastWide SCSI-2 68F
2GB Western Digital WDE2170-007 Ultra Fast Wide 68F
18GB IBM Ultrastar IC35L018UCD210-0 SCSI-LVD/SE U160 80pin
18GB IBM DNES-318350 SCSI-LVD/SE U160 80pin
36GB IBM Ultrastar DDYS-T36950 U160 80pin
36GB Maxstor ATLAS 10K IV U160 80pin
36GB Maxstor ATLAS 10K III U160 80pin

To discover which disk is LDEV 1, power up. See what the primary boot path is. It's likely that your path is 52/56.6.0, and your two drives have jumpers set for address 6 and 5. I believe that 6 in the path has to match the address setting, which is how you join devices to paths. (I'm a software guy, but I try to do my own hardware.)  So the primary path = 56.6.0; I believe LDEV1 = drive with SCSI address 6.

Miller also addressed, so to speak, preferences for data recovery.

You mention you don't have to restore all the data. I hope that means your other drives are on a different volume set. Trying to replace one drive in a multi-drive volume set can be ... undesirable. Files most likely will span over more than one disk. You can use the low level utility DISKUTIL from the ISL prompt (you'll need a bootable disk, or the CD "HP 9000 Offline Diagnostics Environment PA 0409" which HP had available for free at one time).

Using DISKUTIL you which can save off a file from a single disk/LDEV, to recover later (with the VOLUTIL, or RECOVER command). But I don't think you want to go there unless you have to.

In the end, the manager with the failed drive did compare the jumpers on the disks, then changed another of his disks to SCSI address 6. Loading from the SLT commenced, with a note that "there's life in the old girl yet!"