Pinged a mentor of mine on a technology I haven't had a chance to work with to get his thoughts on it. I know that the internet is full of marketing-speak and tech mumbo jumbo, and he has a singular talent for cutting through it and explaining something in terms that really matter. He gave me a pretty solid and concise summary so good I can't help but pass it on. Enjoy!
Wiki linkage:
http://en.wikipedia.org/wiki/IBM_Tivoli_Storage_Manager
"It’s an IBM backup product. Their big efficiency is they do what’s called “incremental forever” backups. Rather than focusing backups on how many weeks you keep a tape for, they look at how many copies of a data set you want to keep. So for example, say you have 10 files you back up nightly. You write a policy that says you want to keep 3 versions of each file on tape. If one file changes every day, it’ll get backed up every day, and Tivoli will release any copy of the file that is more than 3 revisions old. But the other files will only get backed up if/when they change. The problem with Tivoli is that it runs a process of reclamation and consolidation to copy data you need to keep to new media so tapes housing data no-longer-needed can be flushed. If you don’t run this reclamation and consolidation process, you could get into a situation where you need every tape you’ve ever written to restore a single volume.
It’s a neat product, and a different way to look at protecting data. It’s a solid product, well adopted, but hell on your off-site transport costs because you’ll be shuffling tapes around daily to do the reclamation and consolidation.
One other thing you can do is leave all your tapes in the library (for primary copy) and create a synthetic full that you then take off-site."
Wiki linkage:
http://en.wikipedia.org/wiki/IBM_Tivoli_Storage_Manager