What precisely is CloudAgent process? Its files eats space like crazy I have bunch of usual stuff going on in my phone (Samsung Grand, Android 4.1.2) like app auto-updates, Twitter, Dropbox, etc. Most of the time it's clear what the network-related settings for them are (wifi-only all the things) and they are clearly reflected in data stats.

The one exception is "CloudAgent" process, which:


does not really make it obvious what it belongs to (is this part of Android? Samsung custom stuff?)
eats space like crazy (its folder was well over 1GB out of 4GB system space)
eats network, even when not on wifi


While it doesn't really cause any serious issues, it is highly confusing - what it is, what it does and which settings control it?
It's Samsung software, built into the system in certain Samsung phones. Like the Dropbox app, it's a service to automatically upload photos you take on your phone; it connects to your "Samsung account" if you create one. It also integrates with Dropbox to sync photos to the device Gallery; if you have "Camera upload" turned on in Dropbox as well, this probably results in your phone having two copies of each photo: the usual one, and one in CloudAgent's storage.

You can change its settings by going into the main Settings app and choosing Cloud from the Applications manager list (in the Device section). You can clear its data and disable it, or "freeze" the app if your device is rooted, and the only consequence is that photos from Dropbox won't show up in Gallery. If you have the Dropbox app installed as well, Dropbox can still sync (and automatically upload photos) without CloudAgent running.