tape stats

[manu_9]

Is there any way to find out , whether tape is empy or it has data and how much data it has ?

[Michael Tully]

Unless the tape has been created by a commercial backup package, then no.

tar: does not
cpio: does not
fbackup: does not

Normally you can't tell what is on a tape unless you know the format it was written in. You could obviously use some of the above mentioned tools to find out.

[Steve Steel]

Hi

Use dd somùething like

dd if=/dev/rmt/0mn of=/dev/null bs=5000k


Will show blocks in blocks out


Steve stee

[manu_9]

Hi Michael ,
Cna u elaborate it further giving the commands for the same .

[Petr Simik_1]

1. copy block of data to disk
dd if=/dev/rmt/0mn of=/tmp/tape bs=5000k
2. check the format of data - by looking inside the file strings or more you will find what kind of data are stored on tape
fbackup, tar, cpio, dd ....
3. use proper command to list content and check its size

[Michael Tully]

If the tape is written in tar
# tar tvf /dev/rmt/0m 2>/tmp/tape.out

cpio ( I don't touch this one often and it is from memory)
# cpio -icd
fbackup
# frecover -I /tmp/index -f /dev/rmt/0m

As I said there is no real way to get the size of any of these archive backups.

[Rodney Hills]

If
1) you know the format of the tape
2) can read through the entire tape without restoring
3) The tape drive is a newer DDS/DLT/Ultrium drive

Then you could use the "tapeinfo" command. It is available from HP, but I've include a shell archive of the program and documentation as an attachment.

This tool talks to the tape drive controller, which maintains data transfer information. You can reset the counters, read through the tape, then display the counters. It will show both compressed and uncompressed.

HTH

-- Rod Hills