VPS Memory Management & Swap Space Documentation

Essential guide for managing memory on low-RAM VPS instances

Overview

For VPS instances with limited RAM (especially < 2GB), swap space is essential for handling memory-intensive operations like application builds, compilations, and temporary workload spikes.

The Problem

Out of Memory (OOM) errors occur when:

Applications require more memory than physically available
Build processes (Node.js, Next.js, etc.) get terminated
System becomes unresponsive or crashes
Exit code 137 indicates process was killed due to OOM

Swap Space Solution

What is Swap?

Virtual memory extension using disk space
Acts as overflow when RAM is full
Prevents system crashes from memory exhaustion
Essential for low-RAM VPS environments

Current Memory Status Check

# Check current memory and swap
free -h
swapon --show

Creating Swap Space

Method 1: Using fallocate (Faster)

sudo swapoff -a
sudo fallocate -l 2G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Method 2: Using dd (More Compatible)

sudo swapoff -a
sudo dd if=/dev/zero of=/swapfile bs=1M count=2048
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Verify Swap Installation

free -h
# Should show swap in the output