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Create Swapfile

Note that this all requires superuser priveleges.

1. Allocate filespace
   • fallocate -l 2G /swapfile
     • obviously replace 2G with the actual amount you want to dedicate to swap
   • alternatively, dd if=/dev/zero of=/swapfile bs=1024 count=1048576
     • (1048576 = 1024 * 1024) - you can figure out how to get other sizes from here
2. Set permissions
   • chmod 600 /swapfile
3. set as swap
   • mkswap /swapfile
4. Enable swap
   • swapon /swapfile
5. Make permanent
   • add /swapfile swap swap defaults 0 0 to /etc/fstab
6. confirm it's working (doesn't hurt to do this after a reboot to confirm it's persistent)
   • swapon --show

Swappiness

1. Check the current swappiness value:
   • cat /proc/sys/vm/swappiness
2. Modify the swappiness level
   • edit the /etc/sysctl.conf file on line vm.swappiness=** and reboot
   • higher values allow more usage of swap, while lower values try harder to avoid using swap

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     this document last modified: January 28 2020 22:05

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