Tar: tape blocksize error when trying to access single file in ignite tape

[mst]

Hello,

on two itanium machines, both running hpux 11.23 i have created an ignite tape, using
"make_tape_recovery -A" as the command.

Afterwards i tried to restore a single file from the tapes using this syntax:

mt -t /dev/rmt/0mn fsf 1
tar -xvf /dev/rmt/0m /tmp/xyz

However, on both machines i get error messages like "Tar: tape blocksize error".

I also tried to do a "mt -t /dev/rmt/0mn rew" first, but this did not help.

Can anyone give me a hint what i'm doing wron ?

[Kenan Erdey · Accepted solution]

Hi,

try mt -t /dev/rmt/0mn fsf 22 for itanium.

[Steven E. Protter]

Shalom,

I don't think you are doing anything wrong. I think you are using a bad tape.

The procedure looks solid to me. You are moving beyond the header block to get data.

I tried this once for grins and it does work. I much prefer a backup strategy where the only thing I do with Ignite tapes is total system restores and I use fbackup tapes for individual files.

SEP

[OFC_EDM]

Not sure what's going on there with your commands to extract the single file.

What command did you use to backup the file to the tape? Do you know with which block size the tape was written?

Note that with tar The blocking factor must be specified when reading flexible disks and cartridge tapes if they were written with a blocking factor other than the default.

Have you tried to extract the entire ignite file to a temp location?

Then do a tar -xvf /tmp/ignite.file /tmp/xyz? to get the file.

If are able to retrieve the entire ignite file but still can't extract the singe file from it with tar. Then you could resort to transferring the ignite file (if small enough) to a PC and use winzip or rar to extract the file. (If using FTP then ensure it's a binary transfer).

Cheers

[Aneesh Mohan]

Hi MST,

me too suspecting the date format on the tape ,but I like to give a small hint on the restore from a make_tape_recovery image.The file should not have the leading path.

try
mt -t /dev/rmt/0mn fsf 1
tar -xvf /dev/rmt/0m tmp/xyz ---(note the file should not have the leading path)


Thanks,
Aneesh

[V. Nyga]

Hi,

a 'tar -tvf /dev/rmt/0m' should show you the right syntax for a file restore.

Volkmar

[mst]

Thank you a lot for your help so far.

First - the fsf 22 seems so help in a way that the error message does not appear.

but when i do the tar -vx it takes a couple of minutes and then tar quits, without showing any error / status message and no file restored.

i'm gonna try out the other things you have suggested and get back to you.

[mst]

Hello,

so finally i was able to restore single files.

I have used the fsf 22 parameter with the mt command and didn't supply the preceding "/" when trying to restore a file like /tmp/xyz

I don't know why it is "fsf 22" (and not fsf 23, 24, or whatever), but this seems to be important.

That way it worked.

Thank you all for you help.