I have now had this experience in Azure Cloud & Amazon AWS my current issue is on a host running Ubuntu 15.10 but I had similar experiences on CentOS 7.1 and I'm wondering if I'm somehow doing something wrong that is causing the issue.
I add a disk via the aws console and attach it to my host. The disk shows up as xdvf I fdisk xdvf and create new partition primary defaults on every option following this guide: How do I create and tune an ext4 partition from the command-line?
mkfs -t ext4 /dev/xdvf1 mkdir /data mount /dev/xdvf1 /data
Then I proceed to use the /data mount to install apps download stuff ect. I then resized the vm to save money(t2.medium to t2.small)
Now I get: Welcome to emergency mode! After logging in, type "journalctl -xb" to view system logs, "systemctl reboot" to reboot, "systemctl default" or ^D to try again to boot into default mode.
