[hacktree] parallel-debian: A bit more

[Colin Walters <walters src gnome org>]

commit a5a1039c08c9d2d890b1ea3b44b58564353e9283
Author: Colin Walters <walters verbum org>
Date:   Mon Oct 17 16:17:37 2011 -0400

    parallel-debian: A bit more

 parallel-debian/README-testing-multiroot.md |   29 ++++++++++++++++++++------
 1 files changed, 22 insertions(+), 7 deletions(-)
---
diff --git a/parallel-debian/README-testing-multiroot.md b/parallel-debian/README-testing-multiroot.md
index 8c0a134..61279ea 100644
--- a/parallel-debian/README-testing-multiroot.md
+++ b/parallel-debian/README-testing-multiroot.md
@@ -5,11 +5,20 @@ Experimenting with multiple roots
 <http://wiki.debian.org/QEMU#Setting_up_a_testing.2BAC8-unstable_system>
 
 Follow the steps for making a disk image, downloading the business
-card CD, booting it in QEMU and running through the installer.
+card CD, booting it in QEMU and running through the installer.  Note I
+used the QCOW format, since it is more efficient.  Here are the steps
+I chose:
+
+	$ qemu-img create -f qcow2 debian.qcow 2G
+	$ qemu-kvm -hda debian.qcow -cdrom debian-testing-amd64-businesscard.iso -boot d -m 512
 
 Test that the image works after installation too, before you start
 modifying things below!  Remember to remove the -cdrom and -boot
-options from the installation QEMU command.
+options from the installation QEMU command.  It should just look like
+this:
+
+$ qemu-kvm -hda debian.qcow -m 512
+
 
 Modifying the image
 -------------------
@@ -17,8 +26,8 @@ Modifying the image
 You now have a disk image in debian.img, and the first partition
 should be ext4.
 
-The first thing I did was mount the image, and move almost everythig
-(/boot, /var, /etc), except lost+found to a new directory "r0".
+The first thing I did was mount the image, and move the "read only"
+parts of the OS to a new directory "r0".
 
 	$ mkdir /mnt/debian
 	$ modprobe nbd max_part=8
@@ -26,11 +35,11 @@ The first thing I did was mount the image, and move almost everythig
 	$ mount /dev/nbd0p1 /mnt/debian/
 	$ cd /mnt/debian
 	$ mkdir r0
-	$ DIRS="bin boot dev etc lib lib64 media mnt opt proc root run sbin selinux srv sys tmp usr var"
+	$ DIRS="bin dev etc lib lib32 lib64 media mnt opt proc root run sbin selinux srv sys tmp usr"
 	$ mv $DIRS r0 
 
-Now with it still mounted, we need to move on to the next part -
-modifying the initrd.  
+Note that /boot, /home and /var are left shared.  Now with it still
+mounted, we need to move on to the next part - modifying the initrd.
 
 Then I started hacking on the initrd, making understand how to chroot
 to "r0".  I ended up with two patches - one to util-linux, and one to
@@ -48,6 +57,8 @@ $ ./autogen.sh; ./configure ; make
 Now you have a modified "sys-utils/switch_root" binary.  Let's next
 patch the initrd and rebuild it:
 
+$ cd ..
+
 Make a backup:
 
 	$ mkdir initrd
@@ -63,6 +74,10 @@ Repack:
 	$ (cd initrd; find | cpio -o -H newc) | gzip > /mnt/debian/boot/initrd.img-3.0.0-1-amd64.new
 	$ mv /mnt/debian/boot/initrd.img-3.0.0-1-amd64{.new,}
 
+Unmount:
+
+	$ umount /mnt/debian
+
 Running hacktree inside the system
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