I have loved my Nexus 5 since it was released with KitKat, and last evening I decided to enable full disk encryption, which I expected might take around an hour or so. It's now about 12 hours in with no visible change. All I see are the Marshmallow four animated dots. I've never seen any progress display on encrypting the disk, and of course I'm trying to avoid rebooting the phone for fear that the disk will be a jumbled mess and I could either lose my data or even brick the phone.

What is the best course of action at this point, and possible consequences?

  • My suggestion is to plug the charger to the phone and wait with fingers crossed. At the worst case you may have to wipe off the phone and flash fresh factory image - there by loosing the data. The best way to do encryption is to have as low data as possible and then add your content slowly.
    – Narayanan
    Oct 20, 2015 at 10:04
  • Thanks for the response. I need to use the phone soon though! Have you or anyone enabled FDE on a Nexus 5 running Marshmallow and had different results, seen a progress display, or anything different from my description?
    – watou
    Oct 20, 2015 at 10:07
  • I am sorry, I haven't tried enabling encryption. At any rate the 12 hours wait seems to be long. But as I said, what is the phone (beyond the stock image contents) determine how long it will take.
    – Narayanan
    Oct 20, 2015 at 10:54
  • 2
    Thank you, Narayanan, for replying. I got desperate for use of the phone and rebooted it, and it's as if my attempt to encrypt the disk didn't even happen. So at least it's not bricked or lost data...
    – watou
    Oct 20, 2015 at 12:10
  • 1
    @watou - were you ever able to encrypt the device - I just had the same failure - but I still do want to encrypt the device,...
    – Greg
    Nov 25, 2015 at 2:48

3 Answers 3


Could it be that your device is rooted? If yes, google a bit, there are some tutorials which could help. In that case killing or deactivating SuperSU (or similar) could bring success.

Here is what sometimes seem to work (answer is from aikidork):

  1. Install Busybox (I have Stericson version), RootExplorer file manager, a terminal Emulator (or enable USB debugging), and SuperSU (no promises about this working on other root managers!)
  2. Set up a fingerprint lockscreen. Configure ALL your fingers you want to use ahead of time since this won't be configurable later!
  3. Using Root Explorer, copy/backup the following files to external SD:

    /data/system/locksettings.db ,

    /data/system/locksettings.db-shm ,


  4. Kill all running apps.

  5. Launch command prompt in ADB or Terminal Emulator.
  6. Execute su so that your prompt changes from "$" to "#" (you are now root)
  7. Kill the SuperSU daemon to temporarily disable root mode (lasts until reboot):

    pkill -KILL daemonsu

  8. Your root daemon will kick you out of privileged status during shutdown, changing "#" prompt back to "$" (root is temporarily disabled).

  9. DO THIS STEP IMMEDIATELY without rebooting or launching more apps! Go to the default security screen and select Encrypt Device. Set up a password lock screen as required (8 digits with at least one number). Plug in to power if not using ADB. Confirm the encryption operation.
  10. If everything is working well, you will see the encryption screen, a soft-reboot splash screen, and then a progress indicator counting up to 100%. If it moves beyond zero, congrats your encryption is working! Wait for this to finish.
  11. Now, to restore the lock screen, unlock the phone and launch your Root Explorer again.
  12. Restore the three files you backed up earlier to their exact locations, overwriting the replacement ones that the encryption setup created.
  13. Wait for phone to lock (or reboot once more) and confirm that you can unlock the phone with fingerprint.

PS: I currently have the same problem but none of the mentioned solutions helped so far.

UPDATE: This seems to be a common issue when an app is still holding open files. However, there is no official way to determine which process is causing these issue so far and it is recommended to have a chat with the support.

  • These instructions are for the case where you want to use root+encyption+fingerprint lock. Without fingerprint some of the steps might not be needed. Apr 14, 2016 at 2:52

Success! As with others I had to uninstall an app or two to get it to work. Logcat gave the info I needed with these lines:

03-14 12:16:28.983 149 173 W Vold : Tearing down stale mount /mnt/asec/com.exozet.android.catan-1^M

03-14 12:16:29.002 149 173 W Vold : Tearing down stale mount /mnt/asec/ginlemon.flowerpro-1^M

So I removed Settlers of Catan (fun game) and SmartLauncher Pro (googling told me that's what the second app is). After that everything went fine.

I suggest using a file browser to see what you have in /mnt/asec/ and removing those apps. For me those two apps were the only two things in that directory, so it may be that the bug is dealing with stuff in that directory. If so this is a way to identify the problem apps without running logCat. Good luck!


If you're rooted, the encryption process will hang while booting, before the encryption even starts. It's safe to restart your phone when this happens.

If you have a Nexus, unrooting is just a matter of reflashing stock boot.img. This doesn't delete your data or anything, it just replaces the boot partition modified by SuperSU with the default one, which is required by the encryption process.

Step by step guide:

  • Download stock firmware for your phone here: https://developers.google.com/android/images
  • Extract boot.img
  • Turn off your phone, then turn it on by holding volume down + power button. This will get you into the bootloader interface.
  • Connect USB, install drivers
  • Run fastboot flash boot boot.img - assuming fastboot and boot.img are in the same directory
  • Reboot your phone
  • You're un-rooted and the encryption should work now

Just tested this on a Nexus 5. After the encryption's finished, you can root your phone again.

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