开机提示如下：
gave up waiting for root device.
problems:
-boot args (cat/proc/cmdline)
-check root delay =(did the system wait long engough)
-check root =(did the system wait for the right device ?)
-missing modules =(cat/proc/modules; ls /dev)
ALERT! /dev/disk/by-uuid/053e1afd-b3e8-4ea6-a9a3-0aed68ce84da does not exist .dropping to a shell!
BusyBox v1.13.3 (ubuntu 1:1.133.3-/ubuntu11) built-in shell (ash).
Enter 'help' for a list of built-in commands.
