Content extraction problem in 8mm 5GB xyabyte tape.

[ranjank]

I am facing a problem while extracting content from 8mm tape in AIX 4.3.3.Actually the contents of the tape were copied in sun-solaris OS 8.I am getting the following error...

# tar tvf /dev/rmt0
tar: 0511-193 An error occurred while reading from the media.
There is an input or output error.

The status of the tape drive is as follows...

# mt -f /dev/rmt0 status
rmt0 Available 04-A0-00-5,0 5.0 GB 8mm Tape Drive
attribute value description user_settable

mode yes Use DEVICE BUFFERS during writes True
block_size 1024 BLOCK size (0=variable length) True
extfm no Use EXTENDED file marks True
density_set_1 140 DENSITY setting #1 True
density_set_2 20 DENSITY setting #2 True
compress yes Use data COMPRESSION True
ret_error no RETURN error on tape change or reset True
# tar tvf /dev/rmt0
tar: 0511-193 An error occurred while reading from the media.
There is an input or output error.

Can anyone through light on this.....Any help will be greatly appreciated.

Regards,
Ranjan.
Sys Admin.

 

[czins]

Hello Ranjan,

try to set the block_size to 0

Regards
Stefan

 

[ranjank]

Thanks Stefan...

Now it is working fine...Actually i am newbe to AIX....prompt help appreciated.

Regards
Ranjan.
Sys-Admin

 

[ranjank]

Hi

After i set the block size to 0 i was able to view the content of the tape,but when i tried to untar the file it is not happening...Can anyone help me on this..

rgds
Ranjan
Sys-Admin

 

[czins]

Hello ranjank,

you did it with:

tar -xvf /dev/rmt0

?

Reagrds
Stefan

 

[ranjank]

Hi Stefan

ya i used the command tar xvf /dev/rmt0

rgds
Ranjan
Sys-Admin

 

[czins]

Hello Ranjan,

sorry I am out of ideas.

Regards
Stefan

 

[ranjank]

Hi Stefan

Thanks for the prompt help.

rgds
Ranjan

 

[needcoffee]

Try
pax -rf /dev/rmt0 -s/datadirectory

substitute datadirectory for your destination directory. tar is trying to restore the files to their absolute path

needcoffee

 

[MissVick]

Ranjan,
Try this process:

1. Extract a block of data:

chdev -l rmt0 -a block_size=0 <Enter>
dd if=/dev/rmt0 of=/tmp/block bs=128k count=1 <Enter>

2. Determine the blocksize of the block of data:

ls -l /tmp/block <Enter>

3. Try to determine the format of the block of data:

file /tmp/block <Enter>

NOTE: When this is executed, it will give back an archive command. If the 'file' command cannot determine the archive type, it will display the following:
# data or International Language text

4. Change the blocksize of the tape device to that listed on the tape by executing the following:

chdev -l rmt0 -a block_size=<bs from step 2> <Enter>

And then try your tar command again. You can also try just to obtain a TOC with:

dd if=/dev/rmt0 bs=<bs from step 2> count=10 |tar -tvf- <Enter>

Thanks,
MissVick

 

[ranjank]

Thanks All

I got tar archive file by dd command,but it is giving me the following error:--

tar: 0511-169 A directory checksum error on media; 804399808 not equal to 20870.

Any help will be highly appericated.
rgds
Ranjan.

 

[vivek1712]

Hi Ranjan,

Go through this ...

0511-169 A directory checksum error on media: MediaName not equal to Number

Possible Causes
From the command line, you issued the tar command to extract files from an archive that was not created with the tar command.
You issued the tar command for a file that became damaged while being copied over the network.
You issued the tar command for a file that was copied over the network, using the ftp command, but did not specify the binary flag.

Procedures for Recovery
Ensure that the file is in the correct format by running the cpio or the restore command.
Run the sum command on the copied file and also on the original file. Recopy the file if the sizes are different.
Rerun the ftp command using the binary flag to copy the file, then rerun the tar command.

Best Regards,
vivek