Daisy chain Ultrium and DLT?

[Chris Wyld]

I have an Ultrium 460 connected to a ProLiant ML570 G2. I want to connect a DLT 7000 to the Ultrium to restore data to the server from both drives. When I connect the DLT the system hangs at "39160 Port 2 at slot 00, 00:05:01 - SCSI termination not found". The drive(s) are connected to the integrated SCSI controller. I have the DLT drive terminated, but I have also tried it without the termination, same result. Any suggestions?

[Eugeny Brychkov]

It may work ONLY if your DLT7000 drive IS NOT an HVD-interface drive (high voltage differential)! If it's HVD then DO NOT connect it to 29160 and ultrium drive - HVD and LVD are not elecrically compatible. To connect HVD device please use 2944 card
Eugeny

[Chris Wyld]

I have attached the DLT by itself and it works fine. I just can't get it to work in conjunction with the LTO.

[Eugeny Brychkov]

Then your DLT7000 should be single ended. I doubt that LTO 460 can work in single ended mode. This should be a problem
Eugeny

[Joshua Scott]

What's the part number of the DLT-7000? I seem to remember that HP's DLT7000 drives were all HVD SCSI.

[Chris Wyld]

This DLT is a Quantum, if you need the part number I can get it.

[Joshua Scott]

If it's not too difficult, the Part # might help.

What about the cable lengths between the server & the ultrium, and then the cable length between the Ultrium & DLT? If the DLT is Single-Ended SCSI, then the maximum cable length combined between the two is 2.0 meters.

If your cables are longer than that, then you probably just need shorter cables.

[Joshua Scott]

OK, I did some searching and found that the Quantum DLT-7000 comes in SE and Differential
(I'm stupid, I should have thought of my own DLT-70 that's SE in my HP netservers)

Part Numbers:

Single Ended:
TH6BE

Differential
TH6BF

if you have the SE, see my above message. If you have differential, then the Ultrium & DLT won't work together.

[Chris Wyld]

My DLT is single ended. I'm using a 2 meter cable from the server to the Ultrium and a 1 meter cable from the Ultrium to the DLT.
I don't have a cable less than 2 meters that I can use for the Ultrium so I think I'll just connect them separately when I need them.
Thanks for all your input.

[David Ruska]

> My DLT is single ended. I'm using a 2 meter cable from the server to the Ultrium and a 1 meter cable from the Ultrium to the DLT.

You don't want to put the LTO2 on the same bus as a SE DLT7000. It will force the bus to SE mode (assuming you have a LVD HBA).

In SE mode the LTO2 drive will be limited to 40MB/Sec.

The LTO2 drive on a LVD bus is capable of 160MB/Sec burst (if you are on a 160/320 HBA), and sustained transfer rates (i.e. streaming) of 30MB/Sec native and 60MB/Sec compressed (assuming 2:1).

You won't stream the drive with compression enabled on an SE bus.

The other problem with running in SE mode is it limits cable lengths (3M total at 40MB/Sec). This can cause bus hangs and other problems if you have too much cable.