These steps will create an additional swap partition on your system.
1. Create swap partition (This example uses IDE 2nd drive (/dev/hdb), 2nd partition). Use n command and make partition. Change ID to 82 by using t command.At a command prompt type
fdisk /dev/hdb
2. Make swap space using mkswap. At a command prompt type
mkswap -c /dev/hdb2
3. Enable swap space. At a command prompt type
swapon /dev/hdb2
Check swap space using free or top command
4. Edit /etc/fstab to enable next boot
...
/dev/hdb2 swap swap default 0 0
Also See: How to View Swap Info on LinuxLabels: linux, swap space, tools, utils