The following commands allow an existing swap LV to be extended where capacity exists within the volume group.
Check available space for swap growth with:
This will show VFree in RH column
If enough available, then increase swap using:
swapoff -v /dev/VolGroup00/LvSwap
lvresize /dev/VolGroup00/LzSwap -L 10G
swapon -v /dev/VolGroup00/LvSwap
All should be good now for a 10G swap in VolGroup00, named LvSwap