Re: [TCLUG:20799] Need help with SCSI Tape backup

[sos@zjod.net (Steve Siegfried)]

Michael Glaser wrote:
> 
> 
> --- Gabe Turner <dopp@acm.cs.umn.edu> wrote:
> > > 
> > > Question: How do I communicate with this tape
> > drive? It is the only SCSI 
> > > device in the system and I have no experience with
> > SCSI devices.
> > 
> > Since it's a tape, it doesn't have a filesystem so
> > you can't really mount
> > it.  All you do is write to the raw device (like
> > /dev/sd0 or whatever).
> 
> I see... That leads me to my next question then. How
> can I determine what the device name is? Is this
> assigned automatically when the driver loads? I am
> using the BusLogic.o driver for my SCSI card.
> 
> I was under the impression that the device name may
> change based on how you may be trying to use the drive
> - i.e. 'rewind' or 'non-rewind' or maybe even based on
> the size of media you place in the drive. At least
> someone told that is how their SCSI tape drive was
> used in HP-UX. Does Linux do something similar to your
> knoweledge?

/dev/st0 rewinds when you close the device (ie: at the end of a command
like "find . -print | cpio -oa | dd of=/dev/st0".  However, if you're
writing a script and want more than one file per tape, a command like
"/bin/mt -f /dev/st0 fsf 1" won't do what you initially might think.

/dev/nst0 does not rewind. Thus: "/bin/mt -f /dev/nst0 rewind" is
required after use.

hope this help'idly,

-S
 
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  \'o.O'  |  "Linux-- because rebooting is    |  Steve Siegfried
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