Resizing the root partition in CentOS

There are good reasons to have your home directory on a separate partition in CentOS, which is the default when you install. However sometimes, you just need the entire drive on the same partition. I ran into this while installing OpenStack, and it's one of the first things I do to prep an RDO packstack
installation.
First you'll need to unmount the home
directory:
root@centos:~# umount home
Then you can list your logical volumes:
root@centos:~# lvdisplay
Then you'll need to remove the partition. In my case, it was called /dev/mapper/centos-home
so:
root@centos:~# lvremove /dev/mapper/centos-home
Finally, you can extend the root partition to fill the partition:
root@centos:~# lvextend -r /dev/mapper/centos-root /dev/sda2
IMPORTANT: Don't forget to remove the /home
entry from /etc/fstab
or it won't boot!!