If you’re running out of RAM, swap and if there is no more room to create a new swap partition, you’re still left with one more option. Create a swapfile. Here are the steps to follow.
- 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.
- At a shell prompt as root, type the following command with
countbeing equal to the desired block size:
dd if=/dev/zero of=/swapfile bs=1024 count=65536
- Setup the swap file with the command:
- To enable the swap file immediately but not automatically at boot time:
- To enable it at boot time, edit /etc/fstab to include:
/swapfile swap swap defaults 0 0
The next time the system boots, it will enable the new swap file.
- After adding the new swap file and enabling it, make sure it is enabled by viewing the output of the command
Source : Redhat