Google makes A/B partition mandatory for seamless OS updates

[Anonymous]

The A/B Partition design has been there since Android 7 but Google never made it compulsory for Android phone makers (OEMs).

As of news dated 04/04/2020. 

Looks like Google is planning to make 'seamless' OS updates mandatory for all the future smartphones that will run Android 11 or Android R. And it is planning to do that by making 'A/B Partition' setup compulsory, as per a report by XDA Developers. It is worth adding that A/B Partition has been there since Android 7 but Google never made it compulsory for Android phone makers (OEMs).

How does A/B Partition work?

These are two read-only partitions in your smartphones that are exactly the same. Each includes the system, vendor, boot, and product partitions. Usually, the handset runs on one partition, for instance Partition A. Meanwhile the exactly same Partition B stays inactive.

However, when your phone gets an OS update, it downloads the new software in Partition B. On the front end you just see the notification of the OS being downloaded. Meanwhile the update gets downloaded on the Partition B, it gives you time to keep working normally like you do on Partition A.

Once the download is done and when you tap on 'install', the phone reboots seamlessly and runs on the updated Partition B. The Partition A then becomes inactive and untouched. This process is repeated when you get the next update.

The whole point of this is to save time. Before Android 7, when the OS update arrived, the phone took around 25 odd minutes to get updated and run the new OS version. This meant you couldn't do anything on your phone for those many minutes. Here's downloading and installing in one Partition gives you that much time to play around on your phone and then move to the new version without wasting any time.

It is worth adding that even some high-end smartphones such as the Galaxy S20 or Oppo Find X2 doesn't feature A/B Partition. They use their own recovery process to get this done.

So why don't most OEMs want to bring A/B Partitions in their smartphones?

That is because bringing this means sacrificing on some more storage than what is already captured before by the OS and other mandatory system files. However, with handsets featuring 128GB as base storage, it is high time most OEMs bring this feature onboard. However, with Google making it mandatory, one can expect handsets running Android R to get seamless OS updates.

Credits:-   Hindustan times

Hope Samsung realise this and start implementing even in midrange mobiles.

[EdoMadara · Accepted solution]

Also, something worth adding-
If due to any reason the ota package is corrupted, and the resulting update renders the partition B unbootable, the bootloader 'falls back' to partition A after the unsuccessful reboot. So, even if the update package itself has some serious bugs enough to brick the device, (like what happened with M31 once), the device can continue working normally on slot A as the OS there is not corrupted, and you can wait for a revised update without losing on your device. Hence the A/B partition design nullifies the chance of bricking the device via updates too.

[Anonymous]

Yes I thought of adding it in my next post. This post is just a news of google making it mandatory. I saved my notes and articles about partitions, types etc. Will be posting soon.

[Anonymous · Accepted solution]

yes after 3.0

[Anonymous · Accepted solution]

it will be better for users

[Anonymous · Accepted solution]

less chance to produce software loop hole