Comment 0 for bug 1619718

on arm images the vfat used for the boot partition corrupts itself after a few reboots (it is noteworthy that on uboot/arm installations we write a lot more to the vfat. i would actually expect this to happen on x86 systems as well, just a lot later, i.e. after a few kernel updates)

there seem to be various differences in how ubuntu-image creates the vfat ...

in ubuntu-device-flash we use:
mkfs.vfat -F 32 -S 512 -n ... against a loop mounted partition, the -S 512 value gets actually matched against blockdev --getss (and adjusted accordingly if needed)

ubuntu-image currently only calls:
"mkfs.vfat" without any options against an img file that represents the vfat content.

u-d-f also just uses cp against the loop mounted partition while ubuntu-image uses mtools' mcopy to put the files in place ...

the result is that at random boots fsck suddenly starts to rename files in an 8+3 scheme like:
http://paste.ubuntu.com/23124260/ or http://paste.ubuntu.com/23124139/ which results in http://paste.ubuntu.com/23123498/

i spent the whole day trying to tweak the mkfs options but to no avail, the corruption always happens at some point, so my suspicion goes more towards mtools/mcopy now

http://paste.ubuntu.com/23123789/ is the original code that u-d-f uses which does not show such behaviour (i have upgraded the u-d-f rpi2 image over the last 6 weeks daily with new ubuntu-core and occasionally with new pi2-kernel packages without any corruption)