How to list the files on a tape with tar

hp-uxtapetarunix

On a HP-UX OS I have a backup on a magnetic tape created from the SAM.
Everywhere I read the instructions to list-verify the contents of the tape is to use the TAR program:

#tar tvf /dev/rmt/[tapefile]

I've created a new directory /tape with 777 permissions, but when I execute the above command it gives me an error message:

#pwd
/tape
#tar tvf /dev/rmt/0mn >> listtape
Tar: blocksize = 2
directory checksum error

Going after the blocksize error I used another version of the command with the "b" flag:

#tar tvb 2 /dev/rmt/0mn >> listtape
directory checksum error

Anybody have a sugestion? How can I view the contents of the tape? What does this error means?

Best Answer

I did solved this problem and I will post the answer here just in case anyone else have a similar problem.

Since the backup was created using SAM, TAR was NOT used to create the tape. More than likely 'fbackup' was actually used.

In order to see what is on the tape i should use the 'frecover' program.

This command will read the table of contents from the tape (/dev/rmt/0m) and write it out to /tape/tape.idx.

# frecover -I /tape/tape.idx -f /dev/rmt/0m

This:

date +%s

will return the number of seconds since the epoch.

This:

date +%s%N

returns the seconds and current nanoseconds.

So:

date +%s%N | cut -b1-13

will give you the number of milliseconds since the epoch - current seconds plus the left three of the nanoseconds.

and from MikeyB - echo $(($(date +%s%N)/1000000)) (dividing by 1000 only brings to microseconds)

Linux – encrypt tape files with openssl and tar

I think it might have to do with using a block cipher.

I get a similar error when I do:

$ tar czpvf - /test/directory |openssl aes-256-cbc -e -salt -pass pass:password | dd of=/tmp/foo.encrypted.tgz
$ dd if=/tmp/foo.encrypted.tgz conv=sync | openssl aes-256-cbc -d -salt -pass pass:password |tar xzpvf -

But when I use a streaming cipher like rc4, e.g.:

$ tar czpvf - /test/directory |openssl rc4 -e -salt -pass pass:fred | dd of=/tmp/foo.encrypted.tgz

I don't get that error.

Best Answer

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Linux – encrypt tape files with openssl and tar

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