Chroot notes

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Copy an existing root filesystem

This script copies an existing rootfs to one that is to be used in a chroot environment. This copies everything, so it should give you a full environment with everything you need to run anything that would run under the original rootfs. The copy rootfs should look and work exactly like the original. This is useful for creating new versions of rootfs images in embedded systems. This is not efficient if you just want to run a single program under a jail, but this eliminates any doubts and should always "just work".

#!/bin/sh
## mount /dev/sda1 /media/adhoc
## debootstrap jaunty /media/adhoc/rootfs/ http://ports.ubuntu.com/
## cd /media/adhoc/rootfs
TARGET_DIR=$1
cd ${TARGET_DIR}
cp -a /bin .
cp -a /boot .
cp -a /dev .
cp -a /etc .
cp -a /home .
cp -a /lib .
cp --preserve=all --no-dereference /media .
cp --preserve=all --no-dereference /mnt .
cp -a /opt .
cp -a /root .
cp -a /sbin .
cp --preserve=all --no-dereference /srv .
cp -a /usr .
cp -a /var .
## # Enter the chroot jail, which should look exactly like the real rootfs.
## chroot ${TARGET_DIR} /bin/bash -l
## # The /proc filesystem needs to be remounted inside the jail.
## mount /proc /proc -t proc