As we know, merged storage (that is, an internal SD card partition emulated by FUSE in the data partition (/data/media/0 → /storage/emulated/0) is a common thing to be found on recent devices running Kitkat and higher. Now, since this is my internal storage and contains all app and non-app data, will doing a factory reset be true to its name and wipe all of /cache and /data, including /data/media? Or, will it be considerate and keep the things under /data/media?
Note: I am asking this question to clarify a doubt and because I am not willing to do a factory reset to check this on my Nexus 9, which is the only device I have which has merged storage; but note that I asked this question for all devices with merged storage in general, which implies most stock devices with stock Android recovery on Android 4.4 and up. Please do not take the question just in context of Nexus devices. To prevent the question from being considered too broad, here are the constraints:
- The device must have a standard processor (Snapdragon)
- It must be AOSP stock. No OEM customized ROMs (Touchwiz, ZenUI, ColorOS) needs to be considered.
- Devices are not rooted and have stock AOSP recovery.
- AOSP version can be considered for 4.4.4 and 5.0 to 5.1 .
- It must have merged storage.
(An answer relating to Motorola Moto devices and the Nexus 5 & 9 will be enough)
P.S. : I know that TWRP preserves /data/media while doing a wipe of /data and /cache, but I am referring here only to the stock recovery's behaviour in case of a factory reset.