fork: Cannot allocate memory
ENOMEM: not enough memory
Cannot allocate memory - fork(2)

Your system ran out of available RAM and swap space. It can’t create new processes or allocate more memory.

Fix 1: Check What’s Using Memory

# See memory usage
free -h

# Find the top memory consumers
ps aux --sort=-%mem | head -10

# Or use htop for a live view
htop

Fix 2: Kill Memory-Hungry Processes

# Find and kill the biggest process
ps aux --sort=-%mem | head -5
kill -9 <PID>

# Or kill by name
pkill -f "node server.js"

Fix 3: Add Swap Space

# Check current swap
swapon --show

# Create a 2GB swap file
sudo fallocate -l 2G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile

# Make it permanent
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Fix 4: Reduce Application Memory Usage

# Node.js — limit heap size
node --max-old-space-size=512 app.js

# Java — limit heap
java -Xmx512m MyApp

# npm install using less memory
npm install --max-old-space-size=512

Fix 5: Docker Container Memory Limit

# docker-compose.yml
services:
  app:
    deploy:
      resources:
        limits:
          memory: 512M  # Container can't exceed this

# Check container memory usage
docker stats

Fix 6: OOM Killer Logs

# Check if Linux OOM killer terminated your process
dmesg | grep -i "out of memory"
journalctl -k | grep -i "oom"

# The OOM killer picks the process using the most memory
# Fix: reduce memory usage or add more RAM

Related resources

• Docker ENOMEM fix
• Node.js heap out of memory fix
• Linux disk space full fix Related: Kubernetes OOMKilled — How to Fix It