Check if swap is enabled on your server
sudo swapon -s
free -m
Create 256MB or 1GB file
sudo fallocate -l 256MB /swapfile
sudo fallocate -l 1G /swapfile
Check created file
ls -lh /swapfile
Set correct permission. Lock down for root use only
sudo chmod 600 /swapfile
Verify permission
ls -larh /swapfile
Make swap
sudo mkswap /swapfile
Swap on (enable swap)
sudo swapon /swapfile
Verify swap space
sudo swapon -s
Check current swappiness value. Default = 60
cat /proc/sys/vm/swappiness
Set swappiness to 10 (Lower the better for server as swap is not used frequently)
sudo sysctl vm.swappiness=10
For permanent effect
sudo nano /etc/sysctl.confvm.swappiness=10
#add at the end of the file
Check cache pressure. Filesystem is very costly to look up.
cat /proc/sys/vm/vfs_cache_pressure
Set cache pressure (Lower the better for server. Default = 100)
sudo sysctl vm.vfs_cache_pressure=95
For permanent effect
sudo nano /etc/sysctl.conf
vm.vfs_cache_pressure = 95 #add at the end of the file
Make the Swap File Permanent
sudo nano /etc/fstab
Add at the end of the /etc/fstab
/swapfile none swap sw 0 0