Got a crash message while restarting. Get same message after reboot:
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
CPU 1 PID 1 Comm: swapper/0 Not tainted 3.13.0-34-generic #60-Ubuntu
Hardware name: gigabyte technology co, ltd, to be filled by OEM /F2A88XM-HD3