[CentOS] Hierarchial storage management or automated archival to tape

Hi list!

While regular backup solutions like amanda or bacula are very good at their job, ie keeping point2point copies of the files currently on disk, I find them less suited for archiving - having unused files move to tape in duplo and stay there until requested. I've even read of multi-tier solutions - move to slower disks after a week and further on to tape after a month.

Does anyone have some experience or suggestions for this? The project will deal with ~100 TB of growth per year, most files somewhere between 2 and 50 GB.

Yes, it can be done with everything in one filesystem, but I'm concerned about running a full backup every month of 500 TB ;-) Not to mention the time required for recovery in case the filesys crashes....

BR Bent