Will not boot and drops to busybox without mounting file systems

[doctordruidphd]

This problem actually started with 16.10 -- note that LTS 16.04 boots perfectly every time, so I'm inclined to think this is not a hardware problem.

What happens is that grub loads its menu, then starts booting the system. It reaches the "Starting file system quota check" message, then starts trying to mount the file systems from fstab, continues to cycle between mount messages, and eventually times out, dropping to busybox. The mount command shows that /dev/sda1 is mounted as / (along with a bunch of systemd mounts and other system stuff) but no other flel systems. If i use the command mount /dev/sda2, the command appears to execute without error, but it does not mount. mount --all does the same thing -- no errors, but no mount either. systemd-mount /dev/sda2 (for example) just hangs.

Both blkid and systemd-mount --list show the correct list of file systems.

mountall gives the following message:

mountall: Could not connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused.

/dev/sda1 does seem to be mounted, I can ls, edit files, etc., but cannot mount or access other file systems.

On both 16.10 and 17.04, this happens roughly half the time I try to boot. Yesterday, I copied the 17.04 system to another partition, edited the fstab file appropriately, and that new system will not boot at all, always hanging at the same problem. So this is going from an irritation to a serious problem.

I have tried:
update-grub (from chroot)
update-initramfs -u (from chroot)

Not sure where else to go at this point. The problem has gotten much worse in 17.04 -- it is requiring several attempts to boot the system at all.

[doctordruidphd]

This is evidently a known problem. The actual problem is that the system is attempting to mount the file systems before the necessary kernel module/s are loaded. Why this has not been fixed in the init scripts is a question for the crystal ball. The workaround is to delay file system mounting, and there are a couple of ways of doing that, both of which I have tried, and work. One way is to add noauto to each file system entry in fstab, and then mount the files manually in /etc/rc.local with the mount command or the swapon command, as appropriate. The other workaround is to add the _netdev option to each entry in fstab, which delays mounting long enough for the relevant modules to be loaded.