How to use systrace to profile disk I/O in Nexus10 running Android-4.2.1

Question

I am trying to issue the following command line in my desktop terminal to profile some disk data from Nexus 10.

python systrace.py -d --time=10 -o mynewtrace.html

Unfortunately, systrace reports

error: tracing disk activity requires root privileges An error occured while capturing the trace. Output file was not written.

My question is: how to get root access in real Android device like Nexus 10.

Thanks a lot

Answer 1

I think what you need to do is to run adb daemon in the root mode before getting this trace. Try doing this in terminal when your device is connected.

adb root

Hope it helps.

Answer 2

You don't have access to disk category that you have selected.

use following command to check what all categories that current device can support.

$python systrace.py -l 

     gfx - Graphics
   input - Input
    view - View System
 webview - WebView
      wm - Window Manager
      am - Activity Manager
      sm - Sync Manager
   audio - Audio
   video - Video
  camera - Camera
     hal - Hardware Modules
     app - Application
     res - Resource Loading
  dalvik - Dalvik VM
      rs - RenderScript
  bionic - Bionic C Library
   power - Power Management

root and remount the device before running above command.

adb root
adb remount