This is a work in progress containing some scripts that I use to admin my mongodb instances.

This script itereates thru all your collections in the current db and prints relevant information on the size it uses on disk, among other info. Usage:

    mongo --quiet dbname collection-sizes.js

Note: currently it works on a database scope, so you can output the stdout to a file to generate some reports.

Info that is returned:

• Number of documents
• Indicator of capped collection
• Data size
• Total "wasted" size. Size that is allocated by mongo but currently not used on this collection

Also, you will get a total of size and wasted size for the whole database.