Nice. Copy on write file systems will make the flash memory last longer. Also, there is another thread speculating that backing up the SMS messages database while the application has it open may corrupt the backup. With btrfs, the startup or shutdown process could create a snapshot for the entire file system (when files not being modified), and when the phone starts up again, the differences in the snapshot from the last transmitted snapshot (that contains the SMS database in a properly shutdown state) can be sent off device while the phone is operating normally.
2 Likes