Increasing swap size for Linux

Following commands can be used for increasing swap size for Linux

--Swapon for directories
dd if=/dev/zero of=/.swapfile bs=1M count=1024
mkswap -v1 /.swapfile
swapon /.swapfile

--Swapon for new drive / Devices
fdisk /dev/sdb
mkswap /dev/sdb1
swapon /dev/sdb1
make entries in fstab file to keep the swapon after restart as well.