Tape Drive or CDROM Not Found (SCO)
See also Tapes and Tape
There are some odd tape drives not necessarily supported by Unix!. However, most tape drives will.
Creating a tape drive or cdrom should be simple: run "mkdev
tape" or "mkdev cdrom" and answer the questions, relink a new
kernel, reboot and it is done. Unfortunately, people seem to have a
lot of problems with this.
(For the remainder of this article I'll be referring only to
tape drives. Everything said applies equally to cdroms or indeed
any scsi or ide device being added).
Most of the time, the problem is simply that you've chosen the
wrong scsi id or adaptor. Unfortunately, "hwconfig" happily reports
whatever you told "mkdev tape", whether or not a tape is really
there, so this adds to the confusion. YOU CAN'T TRUST "hwconfig"-
just because it says a tape is there does not mean that it is. The
same is true of the boot messages: they are only reporting what
someone put in mscsi, not what is actually there.
On modern releases of SCO (5.0.5 and up), "sconf -v" will show
the actual scsi devices seen on the bus.
UNTIL SCONF SEES IT, IT DOESN'T EXIST.
Don't use sconf prior to 5.0.5- it will crash your system.
It's fine that your scsi controller has a bios scan that shows
the tape- that at least means that it is physically attached. But
until "sconf -v" can see it, the Unix system does not know that it
More on sconf: Tapes and Tape Drives
If your bios doesn't see the tape, fix that problem first. If it
does, but sconf does not, you probably need a better driver for
your scsi controller. It doesn't matter that your hard drive is on
the same controller and that works- if sconf does not list your
tape, and it really is attached (for example you can see it in the
bios scan), you need a better driver.
If sconf does see it, you want to compare what it says to what
"mkdev tape" put into /etc/conf/cf.d/mscsi.
The format is slightly different, but the identical information
sconf: Type Driver Adaptor Bus Target Lun
mscsi: Driver Type Adaptor Target Lun Bus
For example, here's a tape drive at id 2 on the second alad
alad Stp 1 2 0 0
Stp alad 1 0 2 0
What do you do if sconf tells you something different than what
you thought it was when you ran "mkdev tape"? You don't need to run
it again; simply manually edit /etc/conf/cf.d/mscsi, relink the
kernel and reboot.
If the tape is seen, is properly configured but still doesn't
work, you probably have cabling or termination issues: see SCSI.
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