Ubuntu启动时停止的问题gave up waiting for rootgave up waiting for root device

启动时停留在选择系统的那个页面

字符最后一个是（initramfs）   
在后面输入exit后，才能继续启动

暂停页面最后显示代码是
Gave up waiting for root device . Common problems:
    -boot args (cat /proc/cmdline)
    -check rootdelay=(did the system wait long enough?)
    -check root=(did the system wait for the right device?)
    -missing modules ( cat /proc/modules;ls /dev)
ALERT /dev/disk.by-uuid/9d77fcd2-5fc1-419d-939c-af16be94fd34 does not exist.
Dropping to a shell!
BusyBox v1.17.1(Ubuntu 1:1.171-10ubuntu1) built-in shell (ash)
Enter "help" for a list of built-in commands.
(initramfs)  

解决方法：

增加rootdelay参数。

 sudo gedit /boot/grub/grub.cfg    而非  sudo gedit /boot/grub/menu.lst

Kernel /boot/vmlinuz-2.6.27-7-server rootdelay=90 root=UUID=596db294-4759-4f2c-991b-f8be2931a56a ro quiet(如果找不到,找类似的)。再次重启.

原因：
rootdelay设置的时间太短，导致系统还没有正常加载完设备驱动就已经开始寻找root分区，而导致找不到/root分区。