linode-centos6-native-kernel.sh

### Starting from a Fresh CentOS 6.2 Linode
### Enable the native kernel to boot from pvgrub
### It will autoconfigure itself with each yum update.
### This is adapted from a previous script for CentOS 5.5 found here:
### http://library.linode.com/assets/542-centos5-native-kernel-selinux-enforcing.sh
### Provided via the linode wiki
### http://library.linode.com/linode-platform/custom-instances/pv-grub-howto#sph_centos-5
### Provided without warranty, although since it should only be run
### on first box build if your box gets broken simply rebuild it

mkdir /boot/grub/

DISTRO_PLATFORM=`uname -p`
AWK_VERSION_MATCH="{if(\$1==\"kernel.$DISTRO_PLATFORM\") print \$2}"
KERNEL_VERSION=`yum -q list kernel | awk "$AWK_VERSION_MATCH"`

### Write template grub.conf
cat > /boot/grub/grub.conf << EOF
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0)
#          kernel /boot/vmlinuz-version ro root=/dev/xvda
#          initrd /boot/initrd-version.img
#boot=/dev/xvda
default=0
timeout=3
title CentOS ($KERNEL_VERSION.$DISTRO_PLATFORM)
        root (hd0)
        kernel /boot/vmlinuz-$KERNEL_VERSION.$DISTRO_PLATFORM root=/dev/xvda
        initrd /boot/initrd-$KERNEL_VERSION.$DISTRO_PLATFORM.img
EOF

ln -s /boot/grub/grub.conf /boot/grub/menu.lst
yum -y install kernel
if [ $? -ne 0 ]; then
    echo "ERROR aborting..."
    exit 1
fi
mkinitrd -f /boot/initrd-${KERNEL_VERSION}.${DISTRO_PLATFORM}.img $KERNEL_VERSION.$DISTRO_PLATFORM

### Make console work
mount /dev/xvda /mnt
mkdir /mnt/dev/pts
umount /mnt