We have a server with about 15GB of data to backup. I use a 20/40 DLT tape for this task. The backup needs about 2-3 hours which I think is quite ok.

Now comes the funny part. To verify that everything went ok, I tried to restore some files from the beginning of the backup. Now I'm sitting here for 1 hour and the restore process is still going. It seams like tar is reading the whole backup, only to extract a few files from the beginning.
Is this the way tar works? I thought that tar can extract files from the beginning of an archive without going through the whole archive.

Ah, and no, I'm not using the -z option on tar.