SlingStudio video content, including your program stream as well as all video sources, can be consolidated on a single storage device that you choose.
You can record video content on:
SlingStudio saves your video recordings as MP4 files (H.264 video and AAC audio).
For a list of SlingStudio-compatible SD cards and USB drives, take a look at the article that is linked below.
Note that it is not necessary to have an SD card inserted into your SlingStudio unit (or a hard disk attached) to stream live video. You can stream video without interruption ... even when storage media is removed, becomes full, or experiences an error.
You only need storage media present if you're working with a project that requires actual storage.