Lots of SCSI errors on tape unit

[Dan Newcombe]

We have an HP rp5740, with a Surestore 2/40 tape library. It is hooked into a SCSI C1010 Ultra160 Wide LVD A6829-60001 card. The changer is at ID 0, the drives at 1 and 2, and one channel of the card on ID 7 on on ID 6 (changed because it was happening when they were both on ID 7.)

HP hooked the drive up when the machine was installed, and the cableing matches what is in the book.

What we are getting is at the end of this message. Whenever we try to do backups (using Omniback with HP DLT tapes - can't blame another vendor :) they fail after a little bit...sometimes it's right away, sometimes a few gigs. An I/O error is reported by omniback, but the /var/adm/syslog/syslog.log has the messages attached below.

I have checked and all the cables appear to be hooked up correctly and snug. I was looking for any other ideas to try before calling HP support on this issue.

Also, this does not happen only when the drive is in use. As soon as the system is rebooted, before I even log in, the errors are being generated. After that, if you access the tape drives it starts to spit the errors out again.

The errors are in the attached file.

P.S. This thread has been moved from Storage>General to Tape Libraries and Drives. -HP Forum Moderator

[Ken Hubnik_2]

Have you tried swapping the terminators. Perhaps it is bad.

[melvyn burnard]

Well look what was in your log file:

SCSI: Ultra160 Controller at 0/8/0/1: Warning: Data transfer rate stepped down for target 1. Now operating at 20 MB/s (Fast Wide). Possible causes are improper termination, improper cabling, or malfunctioning hardware.


I suggest you get the hardware looked at.

[Ravi_8]

Hi,

by a look at your attached file, i would prefer to log a call to HP

[Vincent Fleming · Accepted solution]

You shouldn't dual-initiate the unit. See answers to your question in the Storage forum.

Good luck!

Vince

[Carlos Fernandez Riera]

By looking at the attach a guess there a only one Surestore 2/40 plugged to two cards, first wiht ID=7 and second with ID=6.

Inside there are two DLT8000 ( Fast_wide???) and one robotics.

So, data can come by two sides....

I remember to that, for shared disk (HASS, Jamaica) you should remove internal terminators in the cards, but i dont know if it is posible for this.

There are on the syslog two interesting sections:

SCSI: Resetting SCSI -- lbolt: 512284, bus: 9 path: 0/8/0/1
SCSI: Reset detected -- lbolt: 512284, bus: 9 path: 0/8/0/1
SCSI: Ultra160 Controller at 0/8/0/1: Warning: Data transfer rate stepped down for target 0. Now operating at 5 MB/s (Slow Narrow). Possible causes are improper termination, improper cabling, or malfunctioning hardware.
SCSI: ATN ignored -- lbolt: 512616, dev: cb091002



SCSI: Ultra160 Controller at 0/8/0/1: Warning: Data transfer rate stepped down for target 2. Now operating at 20 MB/s (Fast Wide). Possible causes are improper termination, improper cabling, or malfunctioning hardware.


As far i know, This cards, Ultra160 Wide LVD, supports only HLVD and Single ended scsi protocols..., and cant share devices HLVD and SE. The terminator should match the devices type.



For shared tapes, you have to disable the EMS monitor for tapes. Also, if your environment is a M/C service Guard, the parameter st_ats_enabled of kernel should be set to 0, and cmtaped service disable.


HTH....???

[Vincent Farrugia]

Hello,

As I already stated... put ONE drive per controller, otherwise you'll have problems.

HTH,
Vince

[Steven E. Protter]

lbolt means something's broke.

If you are confident of the cabling and termination, call in support to replace the tape library.

P

[Dan Newcombe]

As I answered in http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x112831ec5e34d711abdc0090277a778c,00.html, the problem was that HP had wired it up wrong and had several drives on several controllers.

Thanks