Google might soon make the “insufficient space” error obsolete. According to a recent source.android.com documentation, Google is making some changes to its update procedure to make sure that an insufficient space will never stop an update again.
Android 7.0 introduced a new feature called “Seamless Updates”. This introduced a dual system partition scheme “System A” and “System B” partition. During a system update, the phone uses the online System A partition while the update is being applied to the offline System B partition in the background. The installation just requires a simple system reboot to apply the update when the files are all downloaded. During the reboot, the system just switches from Partition A to the newly updated Partition B.
The “out of space” error occurs when the user storage runs out of space which is the temporary download space for the update. Android 8.0 will upgrade the A/B system partition scheme with a “streaming updates” feature. Update data will be directly stored in the offline system partition, written block by block, in a ready-to-boot state. Google will be bypassing the user storage requirement almost entirely, only requiring around 100kb of meta-data.
Since streaming updates are attached to the A/B update system, it’s an optional system that the OEMs can choose to implement or choose to ignore. Android OEMs are quite famous in not following Google’s best practices, and the A/B system is almost non-existent outside Google’s in house devices. For now, it seems like the feature will be exclusive to the pixel family.