Hi,

Could someone kindly tell me how to scan tapes in Linux.  For example,
if there are multiple cpio archives on one tape, how can I find out how
many are on it?  If I am thinking correctly, cpio will only list
whatever is the first archive it finds.

Is it in the method of addressing the device? st0 and nst0 etc? or is
there a utility or command that can essentially ls the tape in the
drive?

Thanks much,
Robert

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2hawks wrote:

>Hi,
>
>Could someone kindly tell me how to scan tapes in Linux.  For example,
>if there are multiple cpio archives on one tape, how can I find out how
>many are on it?  If I am thinking correctly, cpio will only list
>whatever is the first archive it finds.
>
>Is it in the method of addressing the device? st0 and nst0 etc? or is
>there a utility or command that can essentially ls the tape in the
>drive?
>
>
I just wrote a script to do something very similar with some old Amanda
tapes I have.  Yours should be much simpler. I've changed it to do what
I think you want:

=======================
#!/bin/sh

# Script to do a cpio inventory of a tape.
#
# Assumes:    1. /dev/tape -> /dev/nst0 or other non-rewinding tape device
#             2. not more than 100 tape files on the tape
#             3. programs: mt, seq, cpio, grep, wc, and bc are in PATH
#             4. mt reports "EOD" after end of last tape file is reached

mt rewind

for FILENUM in `seq 1 100`
do
echo "============================="
echo " Contents of file $FILENUM: "
echo "============================="
cpio -tv < /dev/tape

# Check to see if we are at the end of the tape:
END_TEST=`mt status | grep EOD | wc -l | bc`
if [ "$END_TEST" = "1" ]
then
mt offline
exit
fi
done
=======================

While this isn't the most elegant script, it gets the job done.  It will
give a "Input/Output" error after it gets to the end of the last file
because the status is EOF until the last cpio is done and then it goes
to EOD.  Anyone have a better solution to this?

I'd run this as:

./ti.sh > tape_1.log

to save the inventory to a file.

Good luck,

Steve

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nice... thanks for that. That solves the cpio end of things for me I
guess.  Now I wonder if that would work the same with tar.... or other
methods of writing to tape.  Trick for me would be to develop a script
that just looked at the tape and did and ls of it... not dependent on
cpio or anything.

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2hawks wrote:

>nice... thanks for that. That solves the cpio end of things for me I
>guess.  Now I wonder if that would work the same with tar.... or other
>methods of writing to tape.  Trick for me would be to develop a script
>that just looked at the tape and did and ls of it... not dependent on
>cpio or anything.
>

cpio will work with tar too.  To check for what type of file is on the
tape you could try putting something like this in your script:

FILE_TYPE=`dd if=/dev/tape bs=32k count=1 | file -`

and then figure out what to do based on what is in the FILE_TYPE variable.

Have fun.

Steve

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You are a gentleman and a scholar sir! Thanks for your assistance.
Btw, does anyone know if mt senses the actual block size when you do a
status (mt -f /dev/nst0 status) or is that based on driver defaults?

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