Also, when you hit the 1024 image limit you have to think about
directory schema to store the images, as the linux filesystem (and also
on other 32 bit systems) will start getting slow, until things like ls
will just give you an error.
We have a system (I didn't work on it, just maintaining it) that has
about 1100 images in a directory. I think we aren't seen any problems
just because it's on a 64bit system.
What filesystem has a 1024 image (file) limit?
Also, on ext3 you can add the dir_index option to a volume to use a
btree index on directories (which, funny enough, is the base for some
databases). Not that ext3 is great, mind you, though it is well
tested.