Swap space extends your VPS memory by using disk as overflow RAM. It prevents out-of-memory crashes on low-RAM servers, though it's much slower than physical RAM.
Checking Existing Swap
swapon --show\nfree -hIf there's no output from swapon --show, no swap is configured.
Creating a Swap File
# Create a 2GB swap file\nfallocate -l 2G /swapfile\nchmod 600 /swapfile\nmkswap /swapfile\nswapon /swapfile\n\n# Make permanent across reboots\necho '/swapfile none swap sw 0 0' >> /etc/fstabTuning Swappiness
Swappiness (0β100) controls how aggressively the kernel uses swap. For a server with good RAM, set it low:
echo 'vm.swappiness=10' >> /etc/sysctl.conf\nsysctl -pA value of 10 means the kernel will only use swap when RAM is 90% full.