External SCSI hard disc

[Stuart Wood]

Hi everybody,

I tried attaching an external scsi hard disc to an HP-UX 11i server last week but without success.

The current configuration is a tape drive (device id 3) attached to a DVD-ROM drive (device id 1). The DVD-ROM drive is terminated. This configuration works fine.

On Friday, after the users had logged out, I brought the server down and attached an external disc drive (device id 5) between the tape drive and the DVD-ROM drive. When I brought the server back up it couldn't see any of the devices. I would not have expected a problem attaching three devices - I'm sure the card can take more than that - and would appreciate any suggestions.

Mark Syder (using colleague's login)

[Pete Randall]

Mark,

99 times out of 100, this has to be a SCSI id conflict. You say that you had three different ID's (3, 1, and 5), but I think that the disk drive either was not set to 5, or conflicted with something else on the same path. When you set the SCSI ID on the drive, did you power it up after setting it? Can you provide an ioscan showing the path your trying to add this drive to (ioscan -kfnH 8/0, for example)?


Pete

[harry d brown jr]

(1) What kind of external disk are you using?
(2) What model is the server?
(3) What SCSI slot & card are you using?
(4) What type of tape drive (model?)?
(5) Can you post an "ioscan -fn" ? and explain which IO path you want to use?

live free or die
harry

[Steven E. Protter]

A lot of the newer scsi devices do not require terminators, they are self terminating. The terminator might be causing the problem.

If you have ioscans from before, run them again and compare, otherwise take the drive out and re-connect, run the ioscan.

SEP

[Stuart Wood]

Three responses in such a short time? I'm impressed! (And grateful.)

I'll start with Pete's request for an ioscan, otherwise this posting will be far too large.

Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
ext_bus 2 0/0/2/0 c720 CLAIMED INTERFACE SCSI C87x Fast Wide Single-Ended
target 6 0/0/2/0.1 tgt CLAIMED DEVICE
disk 3 0/0/2/0.1.0 sdisk CLAIMED DEVICE HP DVD-ROM 305
/dev/dsk/c2t1d0 /dev/rdsk/c2t1d0
target 7 0/0/2/0.3 tgt CLAIMED DEVICE
tape 0 0/0/2/0.3.0 stape CLAIMED DEVICE HP C1537A
/dev/rmt/0m /dev/rmt/c2t3d0BESTn
/dev/rmt/0mb /dev/rmt/c2t3d0BESTnb
/dev/rmt/0mn /dev/rmt/c2t3d0DDS
/dev/rmt/0mnb /dev/rmt/c2t3d0DDSb
/dev/rmt/c2t3d0BEST /dev/rmt/c2t3d0DDSn
/dev/rmt/c2t3d0BESTb /dev/rmt/c2t3d0DDSnb
target 8 0/0/2/0.7 tgt CLAIMED DEVICE
ctl 2 0/0/2/0.7.0 sctl CLAIMED DEVICE Initiator
/dev/rscsi/c2t7d0

While you mull over that I'll dig out the answers to the other questions.

Mark

[Pete Randall]

Mark,

Well, your ioscan seems to eliminate the possiblity that there was another device with SCSI id 5. Are you sure that your disk drive was (properly) set to 5?


Pete

[Mark Grant]

Mark,

It looks like at least your tape drive and DVD are seen by the system OK, are you sure it's not just that the device files have changed?

[Stuart Wood]

The disc drive shows 5 in the device id window - it has shown this since before I attached it (as the id was different from the other two devices, I didn't see any point in changing it). As for whether or not the device id is set properly, how can I tell? At the moment I'm just trusting the display in the window!

The DVD-ROM and tape drive are showing up now, because I've removed the disc drive. When the disc drive was attached nothing on that card showed up.

To answer other earlier questions, the disc drive is an HP 9 Gb drive, product number C6404A. The server is a 9000/800/A500-5X running HP-UX 11i.

Mark

[Pete Randall]

Mark,

The only key to setting the SCSI id "properly" is to make sure it gets power cycled after the change.


Pete

[Stuart Wood]

Final response to an earlier question:

the tape drive is an HP product code C6364A.

Mark

[Trond Haugen]

C6404A is a SMART Storage module and requires a terminator for the last module in the chain. It is a Fast'n'Wide SCSI device.

Regards,
Trond

[Zeev Schultz]

If I see this correctly you're attaching the external Fast-Wide Differential 9 gb drive enclosure to this path:

ext_bus 2 0/0/2/0 c720 CLAIMED INTERFACE SCSI C87x Fast Wide Single-Ended <------

Right?

If yes - it's not supposed to work due to different voltage settings. Either put a FastWide Diff. scsi card and plug the drive or
use SE/LVD enclosure.

Zeev

[Stuart Wood]

It looks as if Zeev has come up with the answer. But can you please explain what an SE/LVD enclosure is? I would guess that SE stands for single ended, but LVD is a bit lost on me.

Thanks for your help.

Mark

[Pete Randall]

Mark,

LVD=LowVoltageDifferential

I'm attaching a little excerpt that I borrowed from Gregory Fruth that explains the different SCSI flavors.


Pete

[harry d brown jr]

and to add to Pete's post:

http://scsifaq.paralan.com/


live free or die
harry