What steps will reproduce the problem? 1. Mount a directory with s3fs and use_cache 2. Do some operations where the cache would fill to 100% of the avail local storage. 3. ??? 4. Profit

What is the expected output? What do you see instead?

It would be an awesome improvement if the cache write/read would use LRU, LFU, 2Q or something http://en.wikipedia.org/wiki/Cache_algorithms and clear the least used items out to make room for newer content.

If you have an s3 bucket with 4 TB of data, the use_cache isn't going to work out of the box.