Google Is Exploring Potentially Using Btrfs In Android

[Spazturtle]

btrfs, which was supposed to be Linux's next generation COW filesystem - Linux's answer to zfs. Unfortunately, too much code was written too quickly without focusing on getting the core design correct first, and now it has too many design mistakes baked into the on disk format and an enormous, messy codebase - bigger that xfs. It's taken far too long to stabilize as well - poisoning the well for future filesystems because too many people were burned on btrfs, repeatedly (e.g. Fedora's tried to switch to btrfs multiple times and had to switch at the last minute, and server vendors who years ago hoped to one day roll out btrfs are now quietly migrating to xfs instead).

Isn't that just an issue with the BTFS driver though not BTFS itself?

[Beherit]

Yeah, compression, subvolumes and snapshots.... wait a sec....

Exactly. It's a phone, not a desktop computer.

[starshipeleven]

Isn't that just an issue with the BTFS driver though not BTFS itself?

That's kinda the same thing though. The driver's logic IS btrfs.

[kreijack]

Sick, yeah.

There are no benefits of using btrfs on a mobile phone or tablet compared to ext4.

BTRFS as a COW filesystem is suppose to be more "flash" friendly. The snapshots are definitely a killer feature even for a mobile phone (which resemble a desktop): think about reconfigure the system to a old "configuration", or providing an old configuration as fallback if an upgrade fail....

[waxhead]

I have run BTRFS happily for years now. Not a single hickup. Let's pretend that BTRFS does not always handle hardware errors correctly and fail. Let's pretend the filesystem is unrecoverable. You know what? That happens for ext3/4 too as well as other filesystems that does NOT have recovery built in. the MD layer does NOT protect against silent corruption. Why do you guys think Google is interested in BTRFS? to avoid bricking devices, perhaps use cheaper memory / storage so simpler failures can be tolerated. It is as simple as to avoid people getting into trouble during their warranty period and to increase profit!

[Sloth]

There are no benefits of using btrfs on a mobile phone or tablet compared to ext4.

The new update scheme has two system and two boot partitions. An update updates the non-active partitions and then sets them active. You can revert if needed, by swapping to the previously active partitions.

That's more than a little wasteful. It'd be awfully, awfully nice to be able to update to a snapshot and then revert.

Compression could be pretty cool, too.

[garegin]

I have run BTRFS happily for years now. Not a single hickup. Let's pretend that BTRFS does not always handle hardware errors correctly and fail. Let's pretend the filesystem is unrecoverable. You know what? That happens for ext3/4 too as well as other filesystems that does NOT have recovery built in. the MD layer does NOT protect against silent corruption. Why do you guys think Google is interested in BTRFS? to avoid bricking devices, perhaps use cheaper memory / storage so simpler failures can be tolerated. It is as simple as to avoid people getting into trouble during their warranty period and to increase profit!

filesystem corruption shouldn't brick the device. Think about it, if the device was bricked from bad software, then it would be bricked before they flash it at the factory. In essense, dead before being born.

[starshipeleven]

Exactly. It's a phone, not a desktop computer.

If you think a mobile device won't benefit from that you are heavily underestimating it.

-compression is obviously better because space savings
-snapshots and subvolumes (same thing for btrfs) allow to compartmentalize the system in a more flexible way than it's done atm, where they just make a dozen of different partitions of fixed size and that's it. Each of these partitions is overprovisioned for obvious reasons (they can't repartition with an OTA), and this eats space.

Also, btrfs adds the seamless multi-device usage (also f2fs does) so you could pretty easily expand your whole system into a sdcard partition.

[starshipeleven]

filesystem corruption shouldn't brick the device. Think about it, if the device was bricked from bad software, then it would be bricked before they flash it at the factory. In essense, dead before being born.

"brick" is a state that requires external recovery tools, and some IT expertise.

Most devices of known brands can be put into factory flash mode (the flashing mode used when they were empty, at the factory) and reflashed because you either have leaked factory tools, reverse-engineered ones or something else that can talk with the boot ROM.

Also if you have flashed a decent third party recovery partition you will be able to recover from a brick by rebooting to that (normal system does not use it so it should not be affected by whatever happens to main system) and reflashing the firmware.

Most users can't do this ecause they either don't know, didn't have the tools, or whatever. And in most cases a debrick done by a professional will not be cheap.

[doublez13]

Sick, yeah.

There are no benefits of using btrfs on a mobile phone or tablet compared to ext4.

How about snapshotting before android upgrades, compression, subvolumes, checksums, mirroring...
Remind me which of those ext4 has?