Extending swap on RH LVM

Here: http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/Deployment_Guide-en-US/s2-swap-extending-lvm2.html

1. Disable swapping for the associated logical volume:
# swapoff -v /dev/VolGroup00/LogVol01

2. Resize the LVM2 logical volume by 256 MB:
# lvm lvresize /dev/VolGroup00/LogVol01 -L +256M

3. Format the new swap space:
# mkswap /dev/VolGroup00/LogVol01

4. Enable the extended logical volume:
# swapon -va

5. Test that the logical volume has been extended properly:
# cat /proc/swaps # free