I have a question on JeOS images being built for ARM boards. I suppose
that we agree that most target SBCs use microSD cards to store and
run the OS. There are exceptions though.

Currently, half of JeOS images are supplied with ext4 and the other half
- btrfs. And frankly speaking, I cannot figure out the rule why some
specific board receives JeOS with ext4 instead of btrfs or vice-versa.
I suppose this was related somehow to btrfs support in u-boot, right?

Another consideration. Does anybody know any research on what FS is
the most friendly to SD cards?

--