Connecting an Ultrium 230 LTO with a K370 (HP-UX 11.0)

[Jose Mosquera]

I am evaluating a SCSI conversor from SCSI/SE to SCSI/LVD to be able to connect an Ultrium 230 LTO with a HP9000/800/K370's box. The supplier of this solution is Paralan Corp. My connection outline is the following one:

[K370's SCSI/SE port] <---> [MS16 SCSI Conversor] <---> [Ultrium 230 SCSI/LVD port]

I have a small doubt about this: The driver "stape" is usually used for units LTO in boxes that support LVD's devices. For this case: Which driver that will be used is?

If the used driver is "stape" I imagine that it will be necessary to install its last patch (PHKL_29247).

We will use the command fbackup/frecover I suppose that we will have to install the last cumulative patch (PHCO_23854).

Omitting performance's inconveniences, any other suggestions or recommendations of previous cases will be grateful.

Best regards,

[Joshua Scott]

SCSI SE and LVD are 100% compatible. All you really need is a cable that connects to both sides.

The SE SCSI connector on the K370 is P/N 28655A. If, as I expect, the Ultrium 230 has a normal 68 pin 'high-density' connection, then all you should need is a adapter cable, which should one of the following p/n depending on the length you require:

C2961A (1.0 m)
C2906A (2.0 m)
C2907A (5.0 m)

I would not recommend using a 5 metre cable unless absolutely necessary, since it tends to degrade performance.

[Jose Mosquera]

Joshua,

Indeed, the K370's SCSI (SE) Parallel Part Number is 28655A (HD50 Female), and the port of the Ultrium 230e is a HD68 female.

Are your **absolutely** sure of your previous recommendation of connection?

Rgds.

[Joshua Scott]

I am confident in the technical aspects, HOWEVER, I would not reccommend using SE SCSI, simply because the BUS speed is limited to 5 megabytes/sec. The U230 Drive has a 15MB/sec. speed native, so the drive would be waiting on the SCSI bus to supply the information. The Ultrium Drives were intended to run on an LVD bus because the LVD ranges from 40 to 320 MB/sec.

All this said, Since your vendor is already going to be using the SE port, I would definitly recommend just using the cable. the 1 & 2 metre cables list for $90 & $100 from HP, but you should be able to get them cheaper than that. I actually have one of the 1 meter cables, if that's all you need.

P.S. I am pretty sure that the 'stape' driver is the one to use, but not completely sure. if you go into SAM to add a tape device, then it should automatically install all the drivers needed.

jscott sourcedirect.com

[Jeff Schussele]

Hi Jose Maria,

Joshua is right on both counts. Although it will work, I wouldn't recommend this configuration for the reason he stated - throughput. Streaming tape drives are just that - streaming. When they can't be "fed" fast enough to keep them streaming, they have to back up & reposition. All this extra movement will wear the tape heads out prematurely & in the case of heavy use - very quickly.
So you need to find an HBA that can keep that tape drive well fed, but that may not be possible on a K370 due to it's slow CPU & bus speeds. You really need a PCI slot, preferrably a turbo slot like in Ls & up to get optimum performance & life out of that drive.

My $0.02,
Jeff

[Joshua Scott]

if you are on a gigabit network, you could attach the ultrium to another server that uses LVD connections, and do the backups over the network. This would produce better performance than direct attaching to the SE SCSI.

There are products that convert HVD (the built-in 68-pin SCSI connector on the K370) to LVD, which may work for you. I have no idea how much they cost, however. I know that fibre-SCSI bridges cost over $10,000 from HP.

Unless you already have the Ultrium 230, or need the larger volume of storage, I would recommend using something like the DLT 80k which can store 80GB compressed, has a 6MB/s Transfer rate, and uses HVD SCSI (20MB/s).

-Josh

[Bill Hassell]

Thew new Ultrium tape drives are way too fast for the K-series boxes. It is doubtful that the processor and associated disks could keep the data streaming fast enough to prevent repositioning (loss of streaming) and this will lead to 100:1 to 500:1 degradation in performance, not to mention the excessive wear on the heads, the tape and the drive itself. If you can get all the equipment with a moneyback guarentee if the drive doesn't work or performs very poorly, give it a try. Otherwise, save yourself a lot of money and get additional DDS drives or slower speed DLT's and use a commercial backup program (like HiBack or Omniback/DataProtector) that can send parallel streams of data to several drives at the same time. NOTE: even DDS and DLT drives willl drop out of streaming if your system can't keep up, or the tape drives are not on separate interfaces.

[Eugeny Brychkov]

I would not do what you want to. It should work, but as Bill said "excessive wear on the heads, the tape and the drive itself"... who knows when it will happen? And officially your solution is not supported
Eugeny