Hi,
Instead of using the tar xvf ...I used tar cvf <device file> for a DLT and the whole of the 50GB data was lost in less than 10sec....The data was not over written for sure. but when i use a tar tvf there is nothing inside. Can i get back the data by any means. If not y.

The data was not overwritten but the table at the begining of the original tar file was - so tar isn't going to see anything.

Check the man page for dd and possibly cpio. One or the other MAY help to dump what was on the tape (although what is dumped may be useless). What OS are you using?

maybe you can recreate the table by performing a tar with the same input directory/file names that were used to create this tape. Then maybe dd from the original tape to the one you just created the table on. This may be impossible, but I offer it as a non-linear thought.

There is also a "man 4 tar" manpage that may offer some help in understanding.

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