HP6000 SE on 9000/K220 for a weekend

[Dianne Johnson]

I'm 2GB short for a 48-60 hour conversion. I have an HP6000 SE disk array with two drives totaling 2+GB attached to an HP3000. It was EOL'd in Feb,2000, but works great. Am I insane to try to attach that array to an HP9000/K220 on its SE port with the 50-high to 50-low cable, then chain the array to a C1537A DAT drive using a 50-low to 68-high? The disk is SCSI 4 and 5, the tape is 0. Will there be a performance hit on the tape?
Any help or comments would be greatly appreciated.

[Curt Thompson · Accepted solution]

Hello Dianne,

Well, call me crazy too, but it all sounds fine to me. Of course, you can expect some performance impact on a SE SCSI bus with multiple peripherals connected; the more you use the HP6000 disk drives the worse your performance will be during a tape transfer. If I had a choice, I would put the tape drive on a SCSI bus by itself to avoid contention that will cause the tape drive to drop down into a stop-start mode instead of streaming. But, it will still work.

By the way, thanks for including the cabling detail in your original post. It helped make your question very clear.

Good Luck,
Curt

[paul courry]

Single ended is single ended is single ended. Just watch your SCSI addresses and everything should be fine.

HOWEVER, your talk of low vs high concerns me. The HP6000 single ended cabinet is old equipment, it only has single ended high stuff in it. Do NOT try to mix this stuff with newer Low Voltage Differential equipment, the repair bill could be high.

Any time you stick a tape drive on the same bus as a disc drive you get performance hits, particularly on higher end drives. There is no way to know how much without doing some tests.

[Curt Thompson]

Hello again Dianne,

I just read Paul C's post to your question and just wanted to confirm your original post. When you said 'high' or 'low' I took it to mean you were talking about high-density and low-density cable connections, right?

Paul is correct regarding connection of LVD to HVD I/O cards and peripherals, but that really doesn't matter here since K-class systems and HP6000 'anything' never included any LVD interfaces.

Good Luck,
Curt

[Dianne Johnson]

Curt,
May have used the wrong terms for the cables. (That's what I get for using unknown TLAs I see.) It's a 50 pin microD to centronics 50 pin from the SE port to the SE disk array. HP is written all over the cable, and it has worked on the HP3000 for many years. It's the cent50 to microD68 that has me worried. Only need to get two backups, but have no spare time.
Thanks for your input. I'll have to do it this week.

[Curt Thompson]

Hello Dianne,

No misunderstanding; I got your meaning in the first post. After Pauls' post, I just wanted to be sure we were still using the same terminology.

Around my work area, we regularily use the term '50-high' or '50-low' to mean exactly the connectors you were describing.

This is coming to you after the weekend. I hope all went well.

Good Luck,
Curt