How to clean up old application folders from prior ROM?

Question

I installed CM10 on my GS2, and during the process I didn't format the file system as I wanted to retain my photos and music on the device. I was aware of an app called "SD Maid" that is supposed to be able to be able to clean up all these old app folders, but it doesn't seem to work. Does anyone know how I can clean up all these folders, or does a person have to just go in and manually delete all of them?

(For an app to do this, the OS would have to have some sort of a referencing system of known installed files & folders, don't know if it has such a thing though.)

Answer 1

If you're changing rom (I.e. from AOKP to CM10) you should always do a factory wipe, data on the sdcard will still be

I'm amazed it booted if you didn't do a factory wipe before flashing a different rom

Answer 2

Let's just clarify one thing: in your Internal Storage (not SD card), different system folders have different meaning:

/system: that's basically where your OS is placed, along with system apps you can't uninstall without using a root file explorer and other core things. I believe it is automatically wiped when you flash a new ROM

/data: that's where apps you install and their data get stored. When you choose to do a "factory reset" or "data wipe", this folder is cleaned. Basically, changes you did get erased, but your system remains untouched. It is a good habit to clean this folder too when you change OS, as retaining the same exact app on different ROMs may result in an unstable or unclean system. Plus your apps may not start at all, as some apps have different version for various ROMs, or create different data for them. To avoid losing everything, various apps for backing up exist.

These folder are separate partitions at all, so there's no risk of damaging one when touching the other.

In the great majority of cases the data (better, userdata) partition include your personal files, such as photos, music and downloads. Just some devices (like Xiaomi ones) separate those things into an emulated SD so that you can do a factory wipe to clear apps and apps data without losing your Documents, with the downside of having a limited space to install apps in.

If you want to delete all old apps, but keep your documents, and dedicated apps don't work, this is my advice:

1. With a root file manager, delete the content of /data folder (this will erase apps and apps data, it is like a factory wipe limited to insalled apps)

2. Wipe the /system folder using your recovery

3. Flash your new ROM

Be careful to do step one only when you have everything ready to perform step three, as it may break your current system. If you want to remove apps but you want to save your saved data (like progress in games), use dedicated apps like Titanium Backup.

Answer 3

my answer is using the app sd III is all for the good a great application to uninstall and reinstall applications to your phones hardware it clearly cleans up the internal storage by moving vice internal storage to the phones modem and then cleaning every single application and downloadable file you then set your data to transfer to the mobile phones external hardware it really does work and doesn't lose any phone data it's as simple as that and I mean simple.