I'm not sure what you mean by continually running, but inotifywait is basically just waiting on an event. As long as the process sticks around it doesn't have to do anything until it gets an inotify.
I don't want to have a running process just for this, I want to be able to take a "snapshot"/"index", store some data on Glacier, and the index on S3, and later, given the index, be able to compute deltas without accessing the full archive store on Glacier.
Is there a reason that you want it in python? Couldn't you do this with diff -q if you only want to know what data has changed? and then use diff to get the deltas?
