Tar: blocksize = 0; broken pipe?

[Kevin Nikiforuk]

Hello,

We initially noticed that we were having problems with some of our backups. There would be an I/O error, the tape marked full when only a small amount of data had been written to it (1%+).

We were told to contact the backup software manufacturer who gave us the following procedure (with our results included). I am tar'ing the data to a jubebox with 8 DLT drives. Same result on all drives.

#tar -cvf /dev/rmt/21mnb /home/XXXX/.profile
a /home/XXXX/.profile 1 blocks

#mt -f /dev/rmt/21mnb rewind

#tar -xvf /dev/rmt/21mnb
directory checksum error

I have also checked the this forum link and followed Elmar's instruction but I get the following error :

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=327706

#tar -tvf /dev/rmt/21mnb
Tar: blocksize = 0; broken pipe?


We have also had the hardware manufacturerer in to check the the jubebox and they were able to view all DLT, switches, device messages and there were no error messages.

We have also used many different tapes just to eliminate the bad tape issue.

Is there anything else I can check to see why we are getting the directory checksum error and Tar: blocksize = 0; broken pipe? error?

Thank you in advance.

[Elmar P. Kolkman]

Have you also checked with specifying the blocksize when tarring to the tapes? Since it is DLT, I would suggest using large blocksizes, at least 32k.

For some reason, tar has trouble reading back the data from the tape.

Since you only backupped (or backed up, a problem for the English speaking people around here) .profile, you could also try to do the rewind and then:
dd if=/dev/rmt/21mnb bs=512 | cat -tv | pg
Just to see if any data was really written to tape and if it contains the correct data.

[Kevin Nikiforuk]

Thanks Elmar, I tried the dd commmand and it did print stuff to the screen but tar still did not work. Did a fbackup and a frecover and we were able to see the data on the tape and work with it. Talking to HP, it is an issue with the tar application itself.

Now it is back to the backup software manufacturer as it is not hardware or O/S.

Thank you for your time.