Is the Messages setting for "Keep Messages" device specific?
I have both a 16gb iPad Mini and a 64gb iPhone 6. It's important for me to keep the full Messages archive on my phone so I can go back and review earlier Messages. I don't care so much on the iPad Mini, since it's more of a consumption device and I'd like to reclaim the available space. However, I still want Messages enabled so that I can send replies when I am using it.
In iOS 8, there's a new setting for the Messages app for Message History. The Setting is called "Keep Messages" and the options are Forever, 1 Year, and 30 days.
I want to know if this is a device-specific setting, or more of an iCloud-level setting. If I set this option to "30 Days" on my iPad, will it only be destructive on my iPad or affect the overall Messages history that I have stored in iCloud and delete Messages from my iPhone as well?
iPad Mini, iOS 8.3