Checking The Cables - HP VS80 - StorageWorks DLT VS 80 Tape Drive User Manual

unix linux frequently asked questions
data protection
drivers FAQs
windows NT
netware
unix - SCO
unix - linux
file:///C|/Documents%20and%20Settings/topher.COL-SPRINGS/Desktop/dltvs80%20manual/document/common/drivers_faqs/eng/ul_q3.htm [11/29/2001 8:34:52 AM]
http://www.hp.com/support/tape may have a later version
frequently asked questions
"How do I tell if my tape drive and drivers are correctly set up?"
contents of this section
tape drive not recognised

checking the cables

checking the tape driver
configuration
This topic is available in English only
tape drive not recognised
There can be several reasons why a tape drive attached to the system will not
respond to commands sent from the application software:
1. Cabling may be too long, too many devices connected, no bus termination,
non-shielded internal cables being used for external applications, badly
seated connectors, tape drive has same SCSI ID as another device etc.
2. Tape Drive not switched on, or faulty
3. HBA faulty.
4. HBA Driver not loaded, or incorrect driver loaded.
5. Tape Device driver not loaded, or incorrect driver loaded.
In our experience, faulty tape drives and HBAs are unlikely to be the cause of the
problem, so all other possibilities should be checked first.
checking the cables
The simplest way to check that the cabling is not at fault is to look for the SCSI
Inquiry string of the Tape Drive, which should be displayed by the SCSI HBA
BIOS (of the HBA to which the drive is attached) when the system is booting.
If the SCSI Inquiry string of the tape drive is seen at boot time, then it is unlikely
that the problem is one of the first three listed above. However, this will not
preclude any SCSI errors which arise from marginal cabling, and which generally
show up during high-speed synchronous data transfer (when performing
backups/restores).
Some systems will not display the SCSI Inquiry strings when booting. However all
Adaptec and Symbios SCSI controllers with a BIOS should do this.
checking the tape driver configuration
In order to diagnose whether the tape driver has been configured correctly you
should CAREFULLY watch the system boot. The HBA settings are always correct,
so if (for example) the Symbios HBA reports that the tape device is present on
channel 1 then the tape must have been configured to be on bus 1.
To try to access the tape device and confirm that the tape drive has been
configured correctly, type the following command:
% mt –t /dev/nst0 rewind
This should then flash the LEDs on the tape device. If it cannot communicate with
the tape device, it will print an error like "no such device or address". Check first
that you have media loaded and that the drive is ready (that is, the drive is not still
in the process of "coming ready"). If you still cannot get an mt command to rewind
the media correctly, first check your cabling and then check whether you have a
SCSI capable kernel (see the answer to the question
drivers I am using at the moment, and what drivers do I need for running tape
backups?".
next question
Go to the next question
when changing drivers in my system?"
related topics
"Are there any important points I need to be aware of
hp learning products
back to list of questions
previous question
next question
"How do I know what disk
© 1999-2001, Hewlett-Packard Company