Comment 8 for bug 1371233

At the same time of upgrade from 13.10 to 14.04 I changed to btrfs which causes incredible trouble (it can't be said often enough that it's irresponsible to offer it as root filesystem without(!) a warning), so there're so many possible reasons for the bug (most of them are bugs for themselves) that for a non-developer it's impossible to provide accurate reports.