Cloning old Quantum drive using 68 pin to 50 pin adapter

[marcuso]

Hello.
I’m now trying to clone a 50 pin SCSI drive on XW8000 machine. The cable is 68 pin SCSI and has a terminator at the end, my dd command is able to copy the drive to USB without errors, but whenever I try to restore the file into an identical HDD, it gives me these errors:

Buffer I/O error on dev sdc, logical block 1792, lost async page write.

Are these bad sectors on the drive? Or do you think a cable problem? I’ve changed my set up twice and still same errors. However, I would think I could boot the drive at least partially, and nothing is coming up.

System is able to recognize drive and access it, as I can create an identical .img file on my USB drive (USB 3, formatted EXT4). I’m using:

dd if=/dev/sda of=/dev/sdb bs=512 conv=sync,noerror

I’m using a simple 50 pin 68 pin adapter to connect drive from cable harness. My master drive is connected to harness and running Ubuntu.

I’ve tried doing this on other 50 pin. SCSI drives, and it worked without problems.

I’m thinking the issue is the drive termination or setup.

The p/n drive I’m trying to clone is TM21S001, and I’ve connected the 50 SCSI drive with the 68 pin SCSI cable using a male 68 pin to make 50 pin SCSI adapter. I’ve cloned other 50 pin SCSIs with it with no issues. I am thinking that my problem is something with termination of LVD v SE. I’ve set the drive to SCSI ID 2. And last thing. I’ve tried this with 3 different quantum drives and they all give me the similar issues

Any ideas on what I could try?

 

[doshea]

I don't know much about more modern SCSI HBAs/controllers, but can you get into the BIOS settings for your HBA and set ID 2 to SE by any chance? I vaguely recall seeing an option like this before.

 

[marcuso]

Thank you!
That’s a great idea, I will try that today and report back!

 

[marcuso]

I tried looking in bios, but I don’t see an option for SE.

 

[GiGaBiTe]

I don't know much about more modern SCSI HBAs/controllers, but can you get into the BIOS settings for your HBA and set ID 2 to SE by any chance? I vaguely recall seeing an option like this before.

That's not how bus selection works in SCSI.

If you attach a SE device to a LVD bus, the host controller will switch the entire bus to SE and the speed of everything drops to the lowest common denominator. The maximum cable length is also reduced significantly. This is why some controllers have a separate physical connector for 50 pin SE devices.

If other drives are working fine, and this error only happens with this specific drive, I would blame the drive being bad.

 

[marcuso]

Thank you for your reply.
That did cross my mind.
However, I’ve tried 4 of the same type of drive (one of which I know was a good drive, and booted correctly just moments earlier) and they all give me the same I/O errors as seen above in the pictures I’ve attached. I really think it’s a set up problem. I’ve tried ‘dd’ into these drives with and without ‘TE’ jumpers on the drive itself. Same results.

In addition I also tried this command on these drives:

dd if=/dev/zero of=/dev/sda bs=512 conv=sync, no error

And same faults with I/O errors.

 

[doshea]

If you attach a SE device to a LVD bus, the host controller will switch the entire bus to SE and the speed of everything drops to the lowest common denominator.

Apologies, I forgot this!

I think I've had issues before with SE devices on SE controllers where I got better reliability when I reduced the speed for that device in the BIOS settings, or told it to use narrow instead of wide transfers, or something. Would those settings be there on a more modern controller?

I wouldn't be surprised if the problems I had were due to bad cabling, lack of termination, or something like that, but a workaround is a workaround

 

[GiGaBiTe]

However, I’ve tried 4 of the same type of drive (one of which I know was a good drive, and booted correctly just moments earlier) and they all give me the same I/O errors as seen above in the pictures I’ve attached. I really think it’s a set up problem. I’ve tried ‘dd’ into these drives with and without ‘TE’ jumpers on the drive itself. Same results.

If you're getting the same error on all four drives, it may be the cabling. LVDS SCSI cables are a lot longer than single ended cables because the differential signalling allows for it. If you run single ended devices on a LVDS cable, you're asking for trouble. Single ended devices use a +5v signal against a ground reference, which can't go as far without running into signal degradation. And do not remove any termination packs from the drives, you're just asking for more trouble. If the termination packs are on the drive, they're probably SIP resistor packs. If you install them backwards, they may not work correctly depending on the type.

If you only have a LVDS cable available, use the connector that is the closest to the controller. You also may want to install a termination resistor pack at the far end of the cable, which is one of these:

NEW!! SCSI Ultra 320 LVD/SE 68-pin Terminator for Internal Cable - Low Profile | eBay

Note : Cable not included. The images you are seeing are actual pictures of the item (cable not included). We specialize in old electronics, audio, video, computers and more!

www.ebay.com

These are generally only needed for U160/320/640, but can help with signal integrity if the bus is in SE mode. If you don't have a short SCSI cable, you may want to invest in one, because the long unused section of the cable is basically a huge antenna that is picking up noise from everywhere.

I think I've had issues before with SE devices on SE controllers where I got better reliability when I reduced the speed for that device in the BIOS settings, or told it to use narrow instead of wide transfers, or something. Would those settings be there on a more modern controller?

Reducing transfer speeds on single ended devices will improve the signal integrity, especially on improper cabling. I would try dropping it down to 5 MB/s if possible. Wide and narrow just refer to the number of bits used in the transactions, narrow is 8 bits and wide is 16 bits.

As for what settings are available, entirely depends on the controller. Many Adaptec SCSI controllers generally have a good range of speed and width settings.

 

[marcuso]

Thank you guys for the reply.
Will try a few things. Been at this for a while lol