A Chroot environment is usually a folder on your filesystem that contains the entire base system for an operating system.
This tutorial will assume you are installing debian squeeze into a folder /chroot/squeeze
You can create a chroot environment itself using debootstrap.
richard@vpceh:~$ debootstrap squeeze /chroot/squeeze http://ftp.uk.debian.org/debian
That sets up the base packages, and then you need to mount the extra filesystems, and create the list of mounted systems.
The /dev filesystem contains all the device nodes for your system. I find it easiest to bind-mount this from the host operating system.
richard@vpceh:~$ sudo mount -o bind /dev /chroot/squeeze/dev
The /proc filesystem contains information about current running processes. This is mounted using the following command
richard@vpceh:~$ sudo mount -t proc none /chroot/squeeze/proc
you can then chroot into the system using the command
richard@vpceh:~$ sudo chroot /chroot/squeeze /bin/bash
Finally, just read the mounted filesystems into /etc/mtab by running
root@vpceh:/# cat /proc/mounts > /etc/mtab
and then you can perform operations as if you were on your own base system :)
