CentOS 6.2 64bit AWS EC2 AMI creation step-by-step

This guy couldn't find any instructions on how to create a CentOS 6 AMI but then fails to provide necessary details in his howto.

http://www.tumblr.com/tagged/centos-?before=1312378836

""I used PV-Grub, which boots into a mini Xen OS first, using one of the Amazon supplied kernels. It then boots the kernel inside the AMI, which happens to be the native kernel supplied with CentOS 6.""

So here are my steps - in as much detail as I recorded - maybe I need to add a bit more explanation to some of the steps so one does not follow them blindly:

1. Start an EC2 instance, preferably a Redhat/CentOS 6, as it already has the tools needed.
• used CentOS ami-697bae00
• used defaults for kernel (aki-8e5ea7e7), ram disk etc
2. Create a 5GB EBS and attach it to the running instance
• vol-xxxxxxx (note volume id)
• /dev/sdf
3. Format (labeling it) and mount the partition, creating a few skeleton directories
• cat /proc/partitions (to verify what dev our volume was attached to .. newer/XEN kernels rename them)
• parted /dev/xvdj
• mklabel msdos
• mkpart primary ext4 1 -1
• set 1 boot on
• quit
• mkfs.ext4 /dev/xvdj1
• mkdir /mnt/ami
• mount /dev/xvdj1 /mnt/ami
• mkdir -p /mnt/ami/{dev,etc,proc,sys}
4. Create base devices for the new install
• /sbin/MAKEDEV -v -d /mnt/ami/dev -x console
• /sbin/MAKEDEV -v -d /mnt/ami/dev -x null
• /sbin/MAKEDEV -v -d /mnt/ami/dev -x zero
5. Create fstab for the new install
• cp /etc/fstab /mnt/ami/etc/fstab
• mount -t proc proc /mnt/ami/proc
• mount -t sysfs sysfs /mnt/ami/sys
6. Install YUM
• mkdir -p /mnt/ami/var/lib/rpm
• rpm --rebuilddb --root=/mnt/ami
• rpm --import --root=/mnt/ami http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
• wget http://mirror.centos.org/centos/6.2/os/x86_64/Packages/centos-release-6-2.el6.centos.7.x86_64.rpm
• rpm -i --root=/mnt/ami --nodeps centos-release-6-2.el6.centos.7.x86_64.rpm
• yum --installroot=/mnt/ami install -y rpm-build yum
7. mkdir /mnt/ami/root
8. cp -v /mnt/ami/etc/skel/.??* /mnt/ami/root
9. mount --bind /proc /mnt/ami/proc
10. mount --bind /dev /mnt/ami/dev
11. cp /etc/sysconfig/network /mnt/ami/etc/sysconfig/network
12. cp -v /etc/resolv.conf /mnt/ami/etc/resolv.conf
13. chroot /mnt/ami/ su -
14. cp /etc/fstab /etc/mtab
15. yum clean all
16. yum groupinstall base
17. yum groupinstall core
18. exit
19. cp -v /etc/sysconfig/network-scripts/ifcfg-eth0 /mnt/ami/etc/sysconfig/network-scripts/ifcfg-eth0
20. Enable fetching of assigned ssh keypair from instance user data at boot time
• cp /etc/rc.local /mnt/ami/etc/rc.local
21. Disable DNS checks and allow root to log into SSH (as in original AMI we started from)
• cp /etc/ssh/sshd_config /mnt/ami/etc/ssh/sshd_config
22. [?? STILL TRUE ??] Disable (as it screws up with Xen) selinux in /mnt/ami/etc/selinux/config
• cp /etc/selinux/config /mnt/ami/etc/selinux/config
23. Configure GRUB "ghost" to satisfy PV-GRUB (menu.lst link to grub.conf pointing to kernel & initramfs)
• \rm -r /mnt/ami/boot/grub
• cp -r /boot/grub /mnt/ami/boot/grub/
24. Update initramfs
• chroot /mnt/ami/ su -
• cd /boot
• mv initramfs-2.6.32-220.2.1.el6.x86_64.img orig_initramfs-2.6.32-220.2.1.el6.x86_64.img
• mkinitrd --force initramfs-2.6.32-220.2.1.el6.x86_64.img 2.6.32-220.2.1.el6.x86_64
25. With the AMI completed, time to sync and unmount the drive (verify unmounts via "cat /etc/mtab")
• sync
• umount /mnt/ami/dev
• umount /mnt/ami/proc
• umount /mnt/ami/sys
• umount /mnt/ami
26. Create a snapshot of the EBS volume
27. Create an AMI from snapshot (root/block device MUST be /dev/sda NOT default of /dev/sda1)
• kernel: aki-8e5ea7e7
• arch: x86_64
• root: /dev/sda