LVD SCSI and SE SCSI compatibility

[Pierre BRUEL]

Is it possible to connect a peripheral with a SCSI LVD interface on a single-ended bus ? For example, a Compaq DLT8000 with a LVD interface on a K380 HPPB-SE interface card.
Has anyone already seen a good paper explaining the differences betwwen LVD,HVD,HDTS,VHDTS ...

[Edward Sedgemore]

I think it may be possible via a convertor cable although you may have support and reliability issues. Check the following links for more info;

http://www.dutchworks.nl/htbin/hpsysadmin?h=3&dn=32858&q=converter%20cable&fh

http://www.dutchworks.nl/htbin/hpsysadmin?h=3&dn=26742&q=LVD%20to%20SE&fh

[Kenneth Platz]

Pierre,

Most LVD SCSI devices should work on a Fast/Wide or Ultra/Wide SCSI bus without any additional converter cables. For example, I have 18G U2W LVD drive sitting on my Ultra/Wide (SE) host adapter at home. The main drawback of using an LVD drive on a SE bus is that you lose all of the additional benefits and speed associated with LVD SCSI and are limited by the cabling requirements of the host adapter.

You may also want to take a look at http://www.scsifaqs.org/, specifically http://www.scsifaq.org/scsifaq.html#Generic099

I hope this helps.

[Andreas Fibiger]

The LVD DLT8000 cannot run on the HP-PB SE Bus. As far as I know, the only Single-Ended controller for HP-PB buses is the HP P/N 28655A, which is a SCSI Narrow SE controller. And The DLT8000 uses a WIDE scsi interface, and that cannot be converted into a NARROW, only the other way round it works.

[Carlos Fernandez Riera]

I agree Andreas...
DLT8000 and HP-PB bus are not suported by HP( i?m sorry).

In the other hand, i have connected SE devices to ultra wide scsi , L and N boxes, but differential scsi dont work.

[Pierre BRUEL]

Thanks for your responses.
So what's the solution to use a DLT8000 on a K380 :
- buy a DLT8000 with a FWD interface to connect it on a FWD-SCSI interface ?
- or, is there a host controller card for K380 on which it is possible to connect a DLT8000 with a LVD interface ?

[Edward Sedgemore]

Were using DLT8000's on K-classes without any problems. They all use FWD connections to HSC FWD controllers on the K's.

Your LVD connection on your DLT8000 is 68 pin, right? If so I dont see why it wont work on an HSC connection on a K. What does it say in the back of your DLT manual about Data Interface ? ours state: Fast Wide Differential SCSI 2, Dual High-Density 68 pin.

The problem is your DLT is a Compaq one - this is definitely not supported on an HP. Weve tried using them here, the firmware loaded by Compaq is different to what HP uses/expects, we couldnt get them to work properly with various HP backup commands. Ditched them and bought HP or Quantum DLT8000's.

[Curt Thompson · Accepted solution]

Hello Pierre,

LVD on the K380, or any K for that matter, just does not appear like it's going to happen. Typical FWD SCSI (or HVD as it applies to HP FWD SCSI interfaces on the K) is probably all we will ever see on our K servers. It appears as if the N & L class system will be the only servers to support both HVD and LVD.

Although both LVD and HVD interfaces are Fast, Wide and Differential, you CANNOT connect an LVD to any K-series FWD SCSI interface, as noted above, since all K-series interfaces are HVD (High Voltage Differential) only.

However, there may be hope! These guys make just about any SCSI convertor you could ever need:

http://www.paralan.com/products.html

Good Luck,
Curt