Comment 14 for bug 883748

No idea of the status of this bug. Running Xubuntu 16.04 and whatever workaround has been applied on my particular system (yes, years later) will cause suspend to work, but not resume, if drives are UNMOUNTED while suspend is taking place. No data corruption is likely at this point if they are left mounted and not removed. I've had this problem where partitions on the same disc as the OS, if unmounted upon suspend, cause resume to fail, and a hard reboot to become necessary, and the system then checks for file errors before booting.
External devices showing as bootable, even with no drive attached, also cause the same failure, so I am sure to remove, say, a multimedia card reader plugged in via USB, with no card in it, which shows the same as an unmounted drive.
I had the same problem back with Xubuntu 12.04 on another machine (whose drive is now trashed after 10+ years of uptime.)
Hope this helps someone searching for resume from suspend failure.