Comment 99 for bug 798414

The only thing I can add here (and hopefully I'm not repeating anyone here) is /boot claims to be about 75% full, and I have also seen it 100% on another system of mine. It appears the problem is during the transition between kernel 4.3 and 4.4. I use an encrypted partition on both systems, one of which is a Surface Pro 3 using secure boot (if that matters to anyone). I have only had one case where the system was unable to boot because of this. Lucky for me I have a cloud backup. The others I caught it in time. I was able to keep the system stable by fixing what appeared to be a dependency error. Then again not rebooting might have also helped. My guess is the Ubuntu installer didn't leave much space on /boot, though normally all that is stored there is a few kernels and related files. Everything appears fine now.