By default, Red Hat Enterprise Linux 6 uses all available space during installation. If this is the case with your system, then you must first add a new physical volume to the volume group used by the swap space. For instructions on how to do so, refer to Section 13.2.2, “Adding Unallocated Volumes to a Volume Group”.
/dev/VolGroup00/LogVol01
is the volume you want to extend by 2 GB): Procedure 14.1. Extending Swap on an LVM2 Logical Volume
# swapoff -v /dev/VolGroup00/LogVol01
# lvresize /dev/VolGroup00/LogVol01 -L +2G
# mkswap /dev/VolGroup00/LogVol01
# swapon -v /dev/VolGroup00/LogVol01
cat /proc/swaps
or free
to inspect the swap space.