I have sony xperia P device and I want to flash its ROM to get Marshmallow(I currently have android 4.0.4).

I want to do full backup of my phone before doing this, I knew about adb backup command, I installed android-tools from my Arch linux repos and issued :

adb backup -all -apk -shared -f momsmobile.ab   

it shows : Now unlock your device and confirm the backup operation. but Nothing shows at all, I have USB debugging enabled and tried to put a password the Developer option "Desktop password for backup".

I also tried following Arch wiki and added udev rules, this is the rule file :

SUBSYSTEM=="usb", ATTR{idVendor}=="xxxx", MODE="0666", GROUP="adbusers"

I'm sure the vendor's and product's id are correct(the real ones aren't provided for privacy).

the above didn't work too, I still get no confirm prompt, although when I issue adb devices I can see mine there.

Basically I have the same issue as this question, only this question has different device model(Sumsung vs Sony) and it's not answered.

Lastly I tried to disable all my antivirus protections, I'm using avast mobile security and disabled every thing but still didn't work.

So what's the problem ?


I don't want to root the device(at least not on backup phase) and I don't want to use any apps.


Might be a little late, but here's what worked for me: put single quotes around the parameters.

adb backup '-all -apk -shared -f momsmobile.ab'
  • This worked for me. I think this is a bug; I'm using android-tools-adb version 5.1.1r36+git20160322-0ubuntu3 from the Ubuntu repos on Ubuntu 16.04.3, and adb version says Android Debug Bridge version 1.0.32. The version from developer.android.com/studio/releases/platform-tools.html (Android Debug Bridge version 1.0.39) seems to work fine without the quotes. – Hitechcomputergeek Sep 27 '17 at 13:45
  • 1
    Single quote didn't work for me on Windows computer. I used: adb backup "-apk -shared -all -system -obb" -f backup10032019.ab and it worked. – Sourav Ghosh Mar 10 '19 at 8:58

I did it! I switched ON "USB Debugging(Security Settings)" in options 'For developers'. I have two options for usb debugging: 1. "USB Debugging" (simple) - this was always ON and 2. "USB Debugging(Security Settings)" - this was OFF.

Phone: Xiaomi Note 3 Pro SE (kate)

On yours phone options maybe will have different names.

  • I am using Redmi Note 4 Global. I did NOT have to enable "USB Debugging(Security Settings)". Just enabling the first USB debugging option worked for me. I used: adb backup "-apk -shared -all -system -obb" -f backup10032019.ab and it worked. – Sourav Ghosh Mar 10 '19 at 9:01

On my LG G5 I changed MTP to RNDIS (USB Ethernet) in option "For Developers"; no quotes needed to get the Backup dialog. Thanks for the tip

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