How to integrate /home back into main partition, then grow partition

It's fairly straightforward, as root:

mkdir /home2
mv /home/* /home2/
umount -fl /home
lvremove /dev/VolGroup/lv_home
mv /home2 /home

• edit your fstab and remove the entry for /dev/VolGroup/lv_home
• check how much space you now have available in VolGroup with vgdisplay and add that much to lv_root with lvextend
• use resize2fs or xfs_growfs as appropriate on lv_root

This process will work if your root filesystem is resizeable (ext4 for example).

1. modify a existing user or create a new user whose home directory is not under /home.
2. verify that you can login as that user and su to root
3. ensure all other users are logged out
4. umount /home - if this fails then user processes may still be using /home. Check with fuser or lsof
5. remount /dev/mapper/VolGroup-lv_home on a temporary mount - /mnt/home for example
6. use rsync, cp -p or some other tool to copy the user home directories from /mnt/home to /home - verify that the permissions and ownerships are correct
7. edit fstab to comment out /home
8. users can now be allow to log back in
9. lvremove /dev/VolGroup/lv_home
10. lvextend -L+921G /dev/VolGroup/lv_root
11. resize2fs /dev/VolGroup/lv_root