安装程序可以从硬盘分区上面用引导文件引导。它们可以在其它操作系统下面启动，或者直接使用 BIOS 提供的引导装载程序直接启动。
A full, “pure network” installation can be achieved using this technique. This avoids all hassles of removable media, like finding and burning CD/DVD images.
This section explains how to add to or even replace an existing linux installation using GRUB.
At boot time, GRUB supports loading in memory not only the kernel, but also a disk image. This RAM disk can be used as the root file-system by the kernel.
Copy the following files from the Debian archives to a convenient location on your hard drive, for instance to
Alternatively, if you intend to keep an existing partition on the hard drive unchanged during the install, you can download the hd-media/initrd.gz file and its kernel hd-media/vmlinuz, as well as copy an installation image to the hard drive (make sure the file is named ending in
.iso). The installer can then boot from the hard drive and install from the installation image, without needing the network.
最后，要配置 bootloader，请进入 第 5.1.5 节 “Booting from Linux using GRUB”。