If you update from CentOS 6.0 to 6.1/6.2 via Yum, etc: edit /boot/grub/grub.conf and /etc/fstab by changing /dev/xvda1 to /dev/xvde1 and /dev/xvda2 to /dev/xvde2 To ensure the server can boot. (You can perform this change via the Console if your server is not booting or getting online)