How to increase the swap filesize in server?

Sometimes, we need to increase the swap file for better performance and procedure as below.

First, Create an 1024MB filesize:

# dd if=/dev/zero of=/swapfile bs=1024 count=1048576

    1. if=/dev/zero : Read from /dev/zero file. /dev/zero is a special file in that provides as many null characters to build storage file called /swapfile.
    2. of=/swapfile : Read from /dev/zero write stoage file to /swapfile.
    3. bs=1024 : Read and write 1024 BYTES bytes at a time.
    4. count=1048576 : Copy only 1048576 BLOCKS input blocks. [ 1024 * 1024MB = 1048576 ]

Make the file as swap filesystem:

# mkswap /swapfile

Set the permission for /swapfile:

# chown root:root /swapfile
# chmod 0600 /swapfile

Activate Swap file:

# swapon /swapfile

Activate /swapfile after Linux system reboot:

# vi /etc/fstab

add the below line.

/swapfile swap swap defaults 0 0