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Shawon Saha
Shawon Saha

Posted on • Updated on

SWAP Management - Create, Activate, Swappiness, Deactivate, Remove [EASY GUIDE]

#linux #tutorial

CREATE

  1. Creating a Swap File Calculating Count Value 
sudo dd if=/dev/zero of=/swapfile bs=1024 count=<1024*desired_swap-size_in_MB>
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Keep block size bs=1024

  1. Set the file permissions to 600 to prevent regular users to write and read the file: 
sudo chmod 600 /swapfile
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  1. Create a Linux swap area on the file: 
sudo mkswap /swapfile
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ACTIVATE

  1. Activate swap file 
sudo swapon /swapfile
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  1. To Make the change permanent open the /etc/fstab file: 
sudo nano /etc/fstab
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  1. Paste following line 
/swapfile swap swap defaults 0 0
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Make Swap permanent

SWAPPINESS

  1. Check swappiness value 
cat /proc/sys/vm/swappiness
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On Ubuntu, the default swappiness value is set to 60

  1. Modify swappiness 
sudo sysctl vm.swappiness=10
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While the swappiness value of 60 is OK for most Linux systems, for production servers, you may need to set a lower value.

  1. Make swappiness permanent To make this parameter persistent across reboots, append the following line to the /etc/sysctl.conf file: 
vm.swappiness=10
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DEACTIVATE

  1. Deactivate swap file 
sudo swapoff -v /swapfile
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REMOVE

  1. Remove the swap file entry /swapfile swap swap defaults 0 0 from the /etc/fstab file. From Step 5.

  2. Finally, remove the actual swapfile from your disk

sudo rm /swapfile
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You can find your swapfile at root directory

swapfile Location

To check the status of swap use free -h or swapon -s

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