Setup Swap file on Linux

Create Swap File on Linux

Step 1
Create Storage File
Type the following command to create 512MB swap file (1024 * 512MB = 524288 block size):
# dd if=/dev/zero of=/swapfile1 bs=1024 count=524288

Where,

    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 /swapfile1.
    of=/swapfile1 : Read from /dev/zero write stoage file to /swapfile1.
    bs=1024 : Read and write 1024 BYTES bytes at a time.
    count=524288 : Copy only 523288 BLOCKS input blocks.

Step 2
 Set Up a Linux Swap Area
# mkswap /swapfile1
# chown root:root /swapfile1
# chmod 0600 /swapfile1
# swapon /swapfile1

Step 3
Activate Swap in fstab

 vi /etc/fstab

/swapfile1 swap swap defaults 0 0

Step 4

 Boot the system


$ free -m