Which directories can I remove in internal SD in Galaxy SII w/ Cyanogenmod? I used ClockworkMod to wipe my Samsung Galaxy SII and install Cyanogenmod 9.1 on it. However, when I mounted my phone on my computer, I see that lots of folders were left on its internal SD by apps from before I flashed my phone.

I was tempted to just delete everything on the internal HD from my computer (running Mac OS X 10.6.8), but I noticed there seems to be critical directories on it like one for Clockwordmod.

Here is a list of the directories on the internal SD via ls -a:



Are there directories in here that are essential to the normal function of the phone? A related question is: When I flash my phone, how to I completely wipe it so that when Cyanogenmod is installed, there will be no traces of previous activity as shown in the screenshot above?

Thank you!
When doing a complete wipe, you can safely delete all directories off the internal storage.  Generally, Android OS will re-create any folders on user areas like internal/external storage if it doesn't find them.

You may want to hold onto (or at least back up prior to deletion) media folders like DCIM and Pictures, for example. Keep in mind that on different devices Camera apps may store photos and videos in other, non-standard directories.  And of course do not delete the clockworkmod folder if you wish to keep the NANDroid backups you've made previously.

Under normal operation, .android_secure is the only directory on either internal or external storage that is absolutely necessary.  It contains apps that were "moved to SD" via settings (if external SD card is not present, apps get moved to internal storage instead.)  If this folder is deleted, it will cause instabilities where these apps would not start (obviously), but you may also have trouble uninstalling them from Android, and would need to manually remove their left-overs (the caches, for example.)

Another notable directory is Android - it contains data for installed apps.