Many time we face the issue with the server performance because of RAM memory, the RAM memory usage is very high but we can’t increase the RAM memory because of any reason like , client won’t have enough finance to increase the RAM on his server or server chassis not having slot to attache the additional RAM memory in that case we can increase the swap memory by using the following simple steps.
1) Check the swap partition by using the fdisk -l command.
For example swap partition is /dev/sda5
2nd) To enable the /swap partition
swapon /dev/sda5
3rd)To enable the swap at boot time, edit the /etc/fstab and add the following line:
/dev/sda5 swap swap defaults 0 0
Now we can change the swap value by creating the swapfile for swap memory.
To create the swapfile use the following command
dd if=/dev/zero of=/swapfile bs=1024 count=3145428
In above example, we have created the RAM swapfile with the 3G, change the value in “count” as per your requirement.
4th) Now make the swapfile as a swap
mkswap /swapfile
Run the following command to enable the swap
swapon /swapfile
For permanent swapfile swap memory add the entry in /etc/fstab, so that /swapfile will mount every time when server rebooted else you have mount it manually after every reboot.
/swapfile swap swap defaults 0 0
Verify the new RAM SWAP memory by using the following command.
cat /proc/swaps
or
free -m
If your server having LVM based partition then refer to the following tutorial to increase the RAM swap memory on LVM based server.