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chroot 妙用

同学的机器出问题了，开机总出"Kernel panic"，估计是内核有问题，但是grub是好的，因为Windows还可以进去。

一开始有个想法，就是用LiveCD启动，然后用aptitude更新，不过考虑到它应该会把文件写在临时的/里，而不是硬盘里，所以本质上不起作用。

后来那个同学Google到了chroot命令，恰好满足了这个要求，这时只要把硬盘mount进来，然后chroot过去，最后aptitude更新一下，ok了！

神奇的chroot,为什么之前没发现？
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