Ultra160 message !

[Ivan Azuara]

Hi !

I was a RP7410 server with HPUX 11i, and has attached "2 C7456A HP DLT 80m Array Module (4 DLT8000 units)". Recently i found the next message in my syslog file:

Aug 20 11:36:53 s_inb_01 vmunix: SCSI: Ultra160 Controller at 1/0/6/0/0: Warning
: Data transfer rate stepped down for target 1. Now operating at 20 MB/s (Fast W
ide). Possible causes are improper termination, improper cabling, or malfunction
ing hardware.

This message only appears after a reboot. The information about my units is the next:

Class I H/W Path Driver S/W State H/W Type Description
========================================================================
tape 0 1/0/0/3/1.3.0 stape CLAIMED DEVICE HP C5683A
/dev/rmt/0m /dev/rmt/c1t3d0BESTn
/dev/rmt/0mb /dev/rmt/c1t3d0BESTnb
/dev/rmt/0mn /dev/rmt/c1t3d0DDS
/dev/rmt/0mnb /dev/rmt/c1t3d0DDSb
/dev/rmt/c1t3d0BEST /dev/rmt/c1t3d0DDSn
/dev/rmt/c1t3d0BESTb /dev/rmt/c1t3d0DDSnb
tape 1 1/0/6/0/0.1.0 stape CLAIMED DEVICE QUANTUM DLT8000
/dev/rmt/1m /dev/rmt/c4t1d0BEST
/dev/rmt/1mb /dev/rmt/c4t1d0BESTb
/dev/rmt/1mn /dev/rmt/c4t1d0BESTn
/dev/rmt/1mnb /dev/rmt/c4t1d0BESTnb
tape 2 1/0/6/0/0.2.0 stape CLAIMED DEVICE QUANTUM DLT8000
/dev/rmt/2m /dev/rmt/c4t2d0BEST
/dev/rmt/2mb /dev/rmt/c4t2d0BESTb
/dev/rmt/2mn /dev/rmt/c4t2d0BESTn
/dev/rmt/2mnb /dev/rmt/c4t2d0BESTnb
tape 3 1/0/14/0/0.0.0 stape CLAIMED DEVICE QUANTUM DLT8000
/dev/rmt/3m /dev/rmt/c5t0d0BEST
/dev/rmt/3mb /dev/rmt/c5t0d0BESTb
/dev/rmt/3mn /dev/rmt/c5t0d0BESTn
/dev/rmt/3mnb /dev/rmt/c5t0d0BESTnb
tape 4 1/0/14/0/0.2.0 stape CLAIMED DEVICE QUANTUM DLT8000
/dev/rmt/4m /dev/rmt/c5t2d0BEST
/dev/rmt/4mb /dev/rmt/c5t2d0BESTb
/dev/rmt/4mn /dev/rmt/c5t2d0BESTn
/dev/rmt/4mnb /dev/rmt/c5t2d0BESTnb

How can I fix this problem ?.


Thank's in advance !

[Curtis Ballard]

Follow the suggestions in the warning. Check the bus for tapes 1 & 2 and see if you can find anything wrong. If the HBA can't transfer data at full speed it will step down the speed automatically to keep things working as well as they can.

Typical problems that cause the transfer rate to step down are long cables, incorrect termination, poor connections.

I always start by disconnecting every point one at a time and checking for damaged pins then reconnect and make certain the screws are tight.

If the problem is still there after checking each connection I'd try changing the terminator then each cable one at a time. If you can't clear up the problem checking cables it is time to start looking at hardware.

If you have time to experiment the cheapest solution is to move things around one at a time until the problem moves with the part.