The Android updates with A/B partitions they have been around since Nougat and have been improved in successive updates, although the implementation until now has been a recommendation and not a requirement. This seems to be changing.
The Android 13 Compatibility Definition Document (CDD) still lists its implementation as optional, but some VTS testing indicates that a device will need to get GMS certified with Android 13. In practice, this means that Android 13 mobile phones must support uninterrupted updateswith A/B partitions.
A/B partitioned updates for “everyone”
Traditionally, when we update our Android, the OTA was downloaded, the mobile was rebooted and all the necessary changes were made before we could use the mobile again, leaving our mobile out of the game for a few minutes. Then Google pulled out of the sleeve partitions A/B.
It is a technically very complex issue, but the essence of which is simple. Mobile phones that support this type of update have: duplicate system partitions (one A and the other B, hence the name) so that when updating the system the changes are made to the inactive partition and while we can continue to use the mobile as if nothing happened. After termination, with a restart, the system changes the partitions: the inactive one becomes active and vice versa.
This has the advantage that the mobile is inactive for much less time -which is needed to reboot- and also in case of a broken OTA, you can go back to the previous version just by leaving the partitions as they were.
But it also has a downside: duplicating partitions means less space is available to users, and that is why even today there are some manufacturers that do not support this type of update, such as Samsung. You can check if it is t7u case with free apps like treble, check Treble Info.
Google has addressed that problem in recent years by using dynamic partitioning and compression, reducing the space required for these mirrored partitions, but these innovations don’t seem to be enough to convince the stragglers. Now everything points to it becoming mandatory from Android 13.
Indications in the tests required to pass the certification required to include Google services indicate that they must support A/B updates and updates with virtual A/B partitions, making it a de facto requirement. At least, for those who want to include Google services on their mobile. It will be necessary to see if Samsung eventually decides to jump on the bandwagon or cling to technicalities to keep delaying implementation.
Via | guard