RE: [cobalt-developers] Onstream Tape Drives & Cobalt Qube 3?

["Tom A. Cox" <tomc@xxxxxxxxxx>]

mt is the magnetic tape control program normmaly provided with a Linux
distribution.  Cobalt does not provide this for some reason.  You can get the
source from RedHat or Mandrake.  Anonymous ftp to
ftp://download.sourceforge.net/pub/mirrors/mandrake/7.2/SRPMS/ and get the
mt-st-0.5b-8mdk.src.rpm file and build the software.

You do not normally need mt to use a SCSI tape device.  mt's function is to do
things like erase or retension the tape, check status and occasionally change
the tape unit's configuration, if the unit supports that.  Otherwise, you can
just ignore it.  All the SCSI tape units I've ever tried just worked out of the
box.

SCSI tape support is part of the kernel.  It is usually built as a loadable
module and is loaded automatically when the /dev/st[0-9] devices are accessed. 
Check your /usr/src/linux/.config file for the ST driver status.  On the Qube
3 for example,  CONFIG_CHR_DEV_ST=m means it is built as a module and located
in  /lib/modules/2.2.16C7/scsi/st.o.  You would use 'insmod st' to load it by
hand if necessary.  BTW, the st device unit numbers do not correspond to SCSI
ID numbers.  During boot, the first tape unit found is assigned st0 and so
forth.  Look at your boot log file, /var/log/dmesg, for something similar to
the following:

  Vendor: HP        Model: T20               Rev: 3.01
  Type:   Sequential-Access                  ANSI SCSI revision: 02
Detected scsi tape st0 at scsi0, channel 0, id 3, lun 0

You can also 'cat /proc/scsi/scsi' to see all your SCSI devices.

I've never encountered a SCSI tape unit that required any configuration.  I
know that for some of the DAT and 8MM tape units, you can turn hardware
compression on or off using the mt program, but I've never needed to do that. 
So, assuming the st.o module is loaded or in the static kernel, all you should
have to do is:  'tar cvf /dev/st0 whatever'

Tom Cox

On Fri, 16 Feb 2001, Kevin Thomson wrote:
> Just tried the following (exactly, and get these responces:
> 
> [root /]# mount /dev/st0
> mount: can't find /dev/st0 in /etc/fstab or /etc/mtab
> [root /]#
> 
> [root /]# mount -f /dev/st0
> mount: can't find /dev/st0 in /etc/fstab or /etc/mtab
> [root /]#
> 
> [root /]# mount /dev/st0 status
> mount: /dev/st0 is not a block device
> [root /]#
> 
> and lastly:
> [root /]# mount -f /dev/st0 status
> [root /]#
> 
> Which if I type mount afterwards to see the mounting points shows me:
> [root /]# mount
> /dev/md1 on / type ext2 (rw)
> none on /proc type proc (rw)
> /dev/md3 on /var type ext2 (rw,nosuid)
> /dev/md4 on /home type ext2 (rw,usrquota,grpquota,grpid)
> none on /dev/pts type devpts (rw,gid=5,mode=0620)
> /dev/st0 on status type unknown (rw)
> [root /]#
> 
> So is this all there is to it? or am I missing something entirely? like
> where I'm mounting this to (ie dir)?
> 
> Thanks
> -Kevin
> 
> -----Original Message-----
> From: robert [mailto:rob@xxxxxxxxxxxxxxx]
> Sent: Friday, February 16, 2001 4:57 AM
> To: Kevin Thomson
> Cc: cobalt-developers@xxxxxxxxxxxxxxx
> Subject: Re: [cobalt-developers] Onstream Tape Drives & Cobalt Qube 3?
> 
> 
> 
> use 'mount' instead of 'mt'
> 
> 
> 
> On Fri, 16 Feb 2001, Kevin Thomson wrote:
> 
> > Alright, I'm definatly up against a brick wall here and I'd really really
> > appreciate some assistance if anyone knows how to install a scsi tape
> drive
> > (specificaly the Onstream ADR50 External) onto a Qube 3 using the built in
> > scsi adapter.  Initialy we plugged it in, rebooted the box and essentialy
> > funbled around looking for commands to mount the drive, then Onstream did
> > Officialy anounce their compatability with Linux and put out this info as
> > they're "installation guide":
> >
> > 	Installation
> >
> > 	The LINUX operating systems have a built in device driver called st. The
> > LINUX installation program will probe your system for SCSI >>	adapters. In
> > some cases, the installation program will ask the user if they have
> attached
> > any SCSI adapters. If you choose YES, a 	dialog box will appear to select
> > from a list of SCSI drivers. Choose the driver that most closely resembles
> > the SCSI adapter. The 	installation program may then give you the
> > opportunity to specify options for the SCSI driver you selected. Most SCSI
> > drivers detect 	your hardware automatically.
> >
> > 	Install as follows:
> >
> > 	1. Shutdown the system and remove power from the system. Connect the tape
> > peripheral to the SCSI bus, adhering to the rules of SCSI for 	bus
> > termination, cable length, and ID selection (See Users Manual for detailed
> > description)
> >
> > 	2.Power on the system, peripherals first.
> >
> > 	3. Boot the system to the system maintenance mode and login as root.
> >
> > 	4. At the command prompt, type : mt -f /dev/st0 status. This should
> display
> > information about the tape drive. If this does not occur, 	re-check your
> > set-up.
> >
> > At first I thought "great now I can continue working on the backup
> software"
> > till I actualy tried "mt -f /dev/st0 status" through telnet and get a
> > "command not found" responce for "mt".  So I'm thinking, okay, maybe they
> > meant Mount, or mnt, no go there either as far as getting the device to
> > work.  Anyways, I call Onstream, The tech support people swear up and down
> > that the mt command stands for magnetic tape drive and its part of the st
> > driver, stating that if that command isn't found that its a fault of the
> > distrobution and I need to get an updated source of the kernel and
> > recompile.
> >
> > So, any ideas/insight into this? I did a little poking around and the "st
> > driver" is present in the kernel source on the Qube 3 but I'm not sure
> > whetehr it is modularized in the compiled kernel or even if its installed
> in
> > the current configuration.  If it is a matter of recompiling the kernel
> > could someone point out a good tutorial for this proccess that works on
> the
> > cobalt procduct(s)?
> >
> > Thanks
> > Kevin Thomson
> > webservices@xxxxxxxxxxxxxx
> >
> >
> >
> > _______________________________________________
> > cobalt-developers mailing list
> > cobalt-developers@xxxxxxxxxxxxxxx
> > http://list.cobalt.com/mailman/listinfo/cobalt-developers
> >
> 
> --
> 
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> HyperAccess Communications, Co.
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-- 
--------------------
Tom A. Cox
Senior Programmer
Tri-Pacific Software
972-620-2520 ext. 23
www.tripac.com