How to add swap on a Linux machine?

I created /dev/hda2 slice on my disk and then it looks like below. Once slice is created, then the next steps are as follows:

# fdisk -l 
Disk /dev/hda: 40.0 GB, 40027029504 bytes
255 heads, 63 sectors/track, 4866 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1        1530    12289693+  83  Linux
/dev/hda2            1531        1780     2008125   82  Linux swap / Solaris
/dev/hda3            3061        4865    14498662+   7  HPFS/NTFS
/dev/hda4            1781        3060    10281600   83  Linux

# df -h /
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda1              12G  8.7G  2.2G  81% /
 
# mkswap /dev/hda2
Setting up swapspace version 1, size = 2056314 kB

# swapon /dev/hda2

Later, I added the swap space entry in /etc/fstab file also so that everytime system reboots, I dont need to do this again and again.