Switching between android versions on Nexus 7 tablet

[nitinmukesh123 11]

Hi,

I recently got Asus Nexus 7 tablet. It conmes with android 4.2 OS.

I want to use it for testing various apps. As it can be upgraded to various versions of android Please guide me how can I switch between various version of android.

So basically if I upgrade the device to 4.3 how can I switch back to 4.2.

One method I can think is to upgrade the android and use factory reset to return to version 4.2, but I want to do it offline so don't have to upgrade online again and again.

Many thanks for any information.

Edited January 27, 2014 by nitinmukesh123

[KanagaDeepan 1,084]

^^^^

So sir ji, you are going to test your apps on various Android versions, right? I guess you may have to downgrade or upgrade again and again soo many number of times. It will strain your device's flash memory. I think a simpler solution will be getting used devices for particular version like say GNexus for 4.2, OG_Razr for 4.1, Pantech burst for 4.0. The used devices will be cheaper but the initial investment will be large, but it will save you TIME, EFFORT, gives immediate results in the long run.

[nitinmukesh123 11]

Many thanks for your suggestion KanagaDeepan.

Actually its web apps and the device is company provided. It is very hard to convince company to have several devices for testing so for the time being I need to use the approach of upgrading/downgrading the OS.

I even tried various options like GenyMotion etc... but none of them are working properly.

[ami1 237]

The only way that I have found for doing this is to use nandroid backups (tar gz image of the full filesystem using any recovery like Clockworkmod etc and running ) of various Android versions on my Nexus 7 and keep restoring the ones I want to test.

However, it requires you to have root and though restoring nandroid backups is fast, creating the backups takes 15 min at least.

I have been thinking to start using multi boot but one problem is that my N7 is only 8GB which is not enough to really have 2-3 versions multiboot. You can search on the XDA Nexus 7 forum for multi boot options.

I had also used chroot to run some linux versions which was good except for the same problem of disk space. Maybe you can try using chroot to run different android versions.

If you only want to test Web Apps then maybe just installing different Chrome versions would work ? (Using some of the backup tools which let you freeze/thaw)

I found Genymotion good to try out different devices/android versions/API versions. What problems do you face in Genymotion ?

[nitinmukesh123 11]

Thanks Amitabh.

My understanding was maybe having some sort of backup tool which can be used to backup the entire OS with apps and can install whenever needed (without jailbreak...etc). Don't want to mess with the device.

I tried Genymotion on windows xp as well on Windows 7.

On Windows XP the android image runs through Oracle VM VirtualBox without any issues but since I need to install play store to install chrome/Firefox browsers I tried to run through GenyMotion itself but it crashes. I tried several options even followed several guides on XDA without success.

On Windows 7, the GenyMotion crashes every time I launch an android image with some weired message. Also tried several machine without success.

[ami1 237]

Nandroid backups do exactly what you want - they make a compressed file of the entire filesystem on the device and this can be unzipped and written back to get the exact system back - with all apps and their progress data, icons and their placements etc etc - everything will be identical.

However, unless you have root there is no way to copy or write back the whole filesystem. Without root you can try the various app backup tools which try to back up all apps and their data but these have never run perfectly for me. They always show some apps as unsupported.

Even if you don't have root, if you can boot to a custom recovery like CWM/TWM etc then you have full control for overwriting the entire filesystem since android has not yet booted.

In this case you will need to run the backup/restore command from the recovery menu Or from adb shell on PC (connected to the tablet with USB).

Genymotion runs very nicely for me on Win 8.1 and I am able to install Play Market and apps. Am using BBM on PC through this method currently. One advantage of Genymotion type of VM methods is that you can just copy the specific android OS folder you are going to tinker with and later just copy it back if you have spoilt something.

I even use a Win8 on VHD (native boot) like this for any R&D type of things so that I can just copy the original file back (even if its 30GB for win8 typically) if installing multiple drivers or apps spoils things beyond repair. (though this happens less with Win8 than with earlier win versions)

Have you tried the NRT (Nexus Root Toolkit) - it will easily let you boot a temporary recovery image (by sending the kernel from PC over ADB) so that you can overwrite the OS with a nandroid back up without rooting the device. It will offcourse unlock the bootloader to do so but you can later lock it back again (that wipes all the data though)

Are you facing problem / crach only in installing Play Market on Genymotion or some other times also ?

[nitinmukesh123 11]

Hi Amitabh,

Many thanks for providing the detailed information.

I will try various apps as suggested by you and figure out which works for me or else I will use the factory reset method which seems to be a simple option for now.

Actually genymotion is only causing problem when I try to run the android image. The same image runs fine on Oracle VM VirtualBox. However from Oracle VM VirtualBox I can't install the play store or apps. I was following a tutorial from xda where I need to run the android image from GenyMotion and then install couple of softwares/drivers by dropping on the running image. This is where I am facing problem as Geny motion never shows any UI of the android image but just crash after few seconds.

[ami1 237]

Yes, dropping the APK files (of play market, chrome etc) does have problems for me too. It may be better to just copy the files to the running android image sdcard folder and install from inside android Or put the files on dropbox or google drive some such web space and then download inside Android using the browser and then install.

[nitinmukesh123 11]

Actually Geny motion is not showing the interface of android image at all when I select the image and play. I will try this on Windows 8.

[ami1 237]

I don't think it is a Windows 7 or 8 problem. Most of the time the problem is because of something going wrong in the configuration of Virtual Box and Genymotion - specially because genymotion changed somethings in their recent version so I had also faced problems of some config mismatch between vbox & genymotion, till I reinstalled everything.

Only thing i can suggest is to un-install vbox & geny. reboot 1-2 times and then reinstall genymotion and vbox exactly as their help says. Remove all config files when you uninstall. Or if you can't find the config files, just give a different folder name when you reinstall (like c:\program files\vbox2 etc). Also delete the genymotion/vbox folders in your user profile. (ie c:\users\username\...)

[nitinmukesh123 11]

Thanks Amitabh.

I actually tried this on several PCs including my home PC and its not working so I am not sure what may be wrong. Hopefully I will be having some free time in next week so I am going to spend some time on this. fingers crossed.