Multiple backups on tape using tar.
I am trying to use tar and mt to manage some of my backups to tape. Each month or so I want to remove the previous months Cold backup .tar files to one tape before deleting them. The problem is when I write any new files to the tape it overwrites the previous backed up files. Is there some trick to appending files into an existing backup or to designate seperate backups, with multiple files contained like January_2009.tar that have just the January backup files, and Feb, etc.