As others have said, the best way is to recover the old server (assuming you can get the hardware).
IBM do offer a recovery service (I've used it), assuming the tapes have not been overwritten, I'd expect you to get everything back. It's not cheap though and I'm pretty sure you'll need a server and drive the same as the original TSM server, along with plenty of disk space. There is also an open source version of the same thing - but I've never tried it. Steven
