I've rooted my worlds-lowest-end-tablet the Azpen A727 successfully a while back. In my quest to recover as much of its tiny memory as possible, I came across a folder called /system/preinstall which has several .apks in it, for software that came with the tablet, that I don't want, and have uninstalled.

When I try to delete them using ES File Explorer, the app successfully gains root, but I get a message "[filename].apk cannot be deleted".

Is there a power greater than root?

1 Answer 1


Indeed there is: "root that knows what it's doing" ;)

  1. you gain no usable free space from deleting stuff below /system, as that's the OS's domain and not used to place user content / user apps
  2. As the user is not supposed to change stuff here (and neither is the OS while running in "normal mode"), /system is mounted read-only – which means you cannot write (nor delete) in this mode. If for some reason (which you should be sure of, know about possible side-effects, and have taken appropriate pre-cautions) you need to write there, you'll first have to re-mount it in read-write mode.
  • 1
    Glad you like it, @OrganicMarble – for more details on the file system structure, you might also wish to take a look at Android Folder Hierarchy. Except for the Dalvik specific stuff, it should still be valid up to Lollipop, though the answer is two years old :) Also relevant: Where Android apps store data?
    – Izzy
    Commented Jul 3, 2015 at 15:25
  • That linked answer was also very informative. Thanks again. I notice that I don't come to this site much, but when I do, you answer my questions. Much appreciated. Commented Jul 3, 2015 at 15:39
  • All except for one, it seems ;) You're always welcome.
    – Izzy
    Commented Jul 3, 2015 at 15:43

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