An interesting commit has shown up recently in the Android Open Source Project (AOSP) relating to Android TV. Specifically relating to the use of USB HDDs on Android TV. The commit is designed to allow Android TV users to make use of USB HDDs with a capacity greater than 2TB. In other words, allowing Android TV device owners better access to a larger collection of personal media stored locally on external drives. What the commit actually looks to do is ensure the GPT is used when a storage device is connected that exceeds 2TB. This is interesting for a number of reasons and most notably as this is one of the major benefits underlying adoptable storage.
When Google launched Android 6.0 (Marshmallow) one of the features announced with that version of Android was "adoptable storage" which allowed Android TV devices (and Android devices in general) to "adopt" an external storage device (such as an external HDD) as internal storage. Essentially, with adoptable storage Android TV users immediately had the ability to increase their device's 8, 16, or higher GB storage limits to a significantly higher limit. In fact, as far as the understanding is, adoptable storage uses GPT already – as like this new commit suggests, GPT is the only way that greater than 2TB drives can be connected. Google's own adoptable storage help page confirms as much stating one of the reasons adoptable storage uses GPT is that it "has file storage limit of ~9ZB." As a result, it would seems more likely that this is not actually part of adoptable storage which would mean that Android TV users may soon be able to connect greater than 2TB USB HDDs to their Android TV boxes and use them without them having to be adopted by the system as internal storage. For reference, while adoptable storage uses GPT, Android TV devices in general do not and instead fall back on the older MBR technology – which is where the original 2TB limit comes from and why the move from MBR to GPT for adoptable storage was so beneficial.
The obvious benefit of a change like this is not only access to the collections of movies, TV shows and games stored on HDDs, but also the hot-swapping nature of a large HDD. For example, someone who owns a 4TB HDD is likely to be constantly updating that HDD with more content – as the collection grows further. When it comes to adoptable storage, once 'adopted' the drive technically becomes incompatible with other devices. This is in-part designed for security but it does mean a user could not set up as adoptable storage, disconnect the drive, move it to a PC, transfer files over, and then reconnect back to the Android TV device, and then access those files. Not to mention, adoptable storage typically requires the HDD to be formatted and in doing so, erases the content. So users cannot access a wealth of content on an adopted HDD to begin with. As already mentioned, while the other solution (maintaining a drive as external –not adopted– storage) provides the hot-swapping option, it is officially capped at at the 2TB compatible limit. So this patch noted in AOSP will remedy that issue completely allowing users to effectively connect any HDD (technically, up to 9ZB), access content, disconnect, connect elsewhere, add more content, reconnect to Android TV again, rinse and repeat.
It is worth mentioning the commit has yet to be merged and so there is no guarantee that this will actually be adopted by Android and become available to Android TV users. Especially considering the patch has been created by a third-party engineer. Although, it is equally worth mentioning the engineer in question is an NVIDIA engineer and with the SHIELD being the go-to Android TV solution for many, it would seem more likely than not that this will be merged to Android at some point in the near future. Barring any unforeseen or unworkable issues arising from the patch.