It would be nice for Obnam to have a tool to answer the question "how much space will be freed if I remove these generations?"

• need to find list of chunks that are used only by the specified gens
• perhaps also count B-tree reduction? cound nodes that are unshared by the relevant trees, or only shared by the trees to be deleted
• however, the B-trees are going to be a fraction (a few percent) of the size of the chunk data, so they're not really worth it

--liw

done ancient wishlist bug, closing. --liw