Do I need swap if I have lots of RAM?

Yes, at least some. Without swap, the OOM killer immediately kills processes when RAM is full. Swap provides a buffer for graceful handling.

Is swap bad for SSD lifespan?

Minimal impact. Modern SSDs have high endurance. Swap write patterns are not significantly different from normal filesystem operations.

Linux Swap Errors — Swappiness, Swap Full, and Memory Pressure

Warningsystem

Overview

Fix Linux swap issues including swap space full, high swappiness causing excessive swapping, creating emergency swap files, and monitoring memory pressure.

Key Details

Swap provides overflow space when physical RAM is exhausted
vm.swappiness (0-100) controls how aggressively the kernel uses swap (default: 60)
A system with no swap can OOM-kill processes without warning when RAM is full
SSDs handle swap much better than HDDs — swap on HDD causes severe performance degradation
Memory pressure can be monitored via /proc/pressure/memory on modern kernels

Common Causes

Insufficient RAM causing heavy swap usage and performance degradation
No swap space configured, causing OOM kills when RAM is full
Swap partition full with no additional swap available
High swappiness value causing unnecessary swapping despite available RAM
Memory leak in application slowly consuming all RAM and swap

Steps

1Check swap usage: free -h and swapon --show
2Create swap file: sudo fallocate -l 4G /swapfile && sudo chmod 600 /swapfile && sudo mkswap /swapfile && sudo swapon /swapfile
3Make permanent: add '/swapfile none swap sw 0 0' to /etc/fstab
4Adjust swappiness: sudo sysctl vm.swappiness=10 (persistent: add to /etc/sysctl.conf)
5Monitor pressure: cat /proc/pressure/memory (shows some/full pressure metrics)