Device: Unbranded Android tablet
Android: 2.2

I was trying to root my tablet using my Ubuntu 11.10 machine.

I followed the following instructions from a site:

1. adb Install Superuser.apk
2. adb push busybox /sdcard/
3. adb push su /sdcard/

In the same terminal, now we open adb:

adb shell

Enter the command for superuser


Now, you will copy and paste these commands:

1. mount -o remount,rw /system
2. mv /system/xbin/su /system/xbin/oldsu
3. cp /sdcard/busybox /system/bin/busybox
4. cp /sdcard/su /system/bin/su
5. chmod 06755 /system/bin/su
6. chmod 0755 /system/bin/busybox
7. ln -s /system/bin/su /system/xbin/su
8. exit su (may say something about a bad number
9. exit
10. adb reboot

I could not run the first mount command, but still continued with rest of the 9 commands. Then, I ran a root checker app after reboot to check whether my device was rooted. It indicated no root access.

I then again ran adb shell, and then on running su, it gave an error:

su: 1: Syntax error: "(" unexpected

Now, I am not even able to delete this file. I am stuck and since it's my first time trying to root an Android device. I have no idea what should be done now to resolve this problem and successfully root my device.

  • Off topic, this is a common shell scripting problem and not Android-related at all. Step 8 is not a command but a comment, you probably forgot the '#' in front of it. Or just omit step 8. Even if you try to execute step 8, step 9 will run anyway. No problem here.
    – ce4
    Aug 4, 2013 at 9:15
  • 1
    @ce4 But he's not able to run the first mount command. What could be the problem with that?
    – geffchang
    Aug 4, 2013 at 9:44
  • 1
    If he cannot run the first command, the following ones should fail as well. Besides, how should that work? Immediately after adb shell he issues su – which is not yet there. Not being root, mount cannot work, so the stuff cannot be copied to the /system partition. What confuses me a little is step 2 – which implies there is a su available already before rooting. I never checked that; is that the case? So one could get root permissions via ADB on a not-rooted device? I doubt that, since why then do we need exploits to root devices?
    – Izzy
    Aug 4, 2013 at 10:06
  • It could be one of those pre-rooted tablets, but why would be there a guide to root an already rooted device...? Aug 4, 2013 at 10:18
  • Before doing this all, when i ran su in adb shell, # was coming. But now an error is coming. Is there any way that i can do something about that file?
    – zephyr
    Aug 4, 2013 at 10:21

1 Answer 1


Obviously the su binary you installed does not work well with your system. As you luckily created a backup of the original su executable, recommendation is to revert the incompatible changes first:

adb shell
$ oldsu
# mount -o remount,rw /system
# rm /system/xbin/su /system/bin/su
# cp /system/xbin/oldsu /system/xbin/su
# exit
$ exit
adb reboot

Explanation: Start adb shell and become root (using the working oldsu executable). Delete /system/xbin/su (which is only a symlink now) and the incompatible /system/bin/su, then copy the working su back to where it belongs. Then exit the root shell and finally adb shell. The reboot is optional, and should not be needed. Also optionally you could remove busybox (or keep it if it works). Before exiting adb shell you might wish to test whether su works again, just to be sure (which is why I wrote cp for this: if anything goes wrong, you still have your oldsu available).

With those steps, you should at least have everything in working order again, and this issue is solved. Updating to a newer Android version is a separate issue: Please check the tag, as corresponding questions already exist. Same for the ROM you might need (check the tag for that, and in also check the tag-wikis for update and rom).

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