Sometimes it is necessary to add more swap space after installation. For example, you may upgrade the amount of RAM in your system from 64 MB to 128 MB, but there is only 128 MB of swap space. It might be advantageous to increase the amount of swap space to 256 MB if you perform memory-intense operations or run applications that require a large amount of memory.

You have two options: add a swap partition or add a swap file. It is recommended that you add a swap partition, but sometimes that is not easy if you do not have any free space available.

To add a swap partition

#fdisk /dev/sdb

#mkswap /dev/sdb2

#swapon /dev/sdb2

#/etc/fstab

To add a swap file

Determine the size of the new swap file and multiple by 1024 to determine the block size. For example, the block size of a 64 MB swap file is 65536.

#dd if=/dev/zero of=/swapfile bs=1024 count=65536

#mkswap /swapfile

#swapon /swapfile

#/etc/fstab

#/swapfile               swap                    swap    defaults        0 0