SWAP space serves as an overflow area when physical RAM is exhausted, but its role has evolved with modern memory management. On systems with 2-4GB RAM, the decision isn't as straightforward as the old "2x RAM" rule.

# Check current swap usage:
free -h
# or
swapon --show

Hibernation requirements: If you plan to use hibernation, your swap must equal or exceed your RAM size.

Workload characteristics: Memory-intensive applications like Docker containers, databases, or IDEs may benefit from swap even with "enough" RAM.

For a 2GB RAM system:

# Minimum viable swap
sudo fallocate -l 1G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile

For a 4GB RAM system:

# Balanced approach
sudo dd if=/dev/zero of=/swapfile bs=1M count=2048
sudo mkswap /swapfile
sudo swapon /swapfile

With sufficient RAM and no hibernation needs, you might omit swap entirely. Test memory pressure with:

vmstat 1 5

# Temporary adjustment (0-100 scale)
sudo sysctl vm.swappiness=30

# Permanent change
echo "vm.swappiness=30" | sudo tee -a /etc/sysctl.conf

Regularly check swap usage patterns to right-size your configuration:

# Comprehensive memory report
cat /proc/meminfo | grep -i swap

# Process-level swap usage
sudo smem -s swap -r

Modern Linux systems with sufficient RAM (8GB+) often don't require swap space, but for 2-4GB systems, the equation changes. SWAP serves three critical purposes:

• Acts as emergency overflow when RAM is exhausted
• Enables hibernation functionality
• Allows the kernel to move idle pages out of RAM

For development machines where you might run memory-intensive applications:

# Calculate recommended swap (RAM ≤ 2GB)
swap_size = ram_size × 2
# For 2-4GB systems
if ram_size > 2 and ram_size ≤ 4:
    swap_size = ram_size + 2

For headless servers running few processes:

# Minimum viable swap for stability
swap_size = max(ram_size × 0.5, 1GB)

Creating swap using a file (flexible approach):

sudo fallocate -l 2G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
# Add to /etc/fstab:
/swapfile none swap sw 0 0

SWAP on SSDs requires special tuning to prevent excessive wear:

# Reduce swapiness for SSD systems
echo 'vm.swappiness=10' | sudo tee -a /etc/sysctl.conf
# Prioritize RAM cache clearing
echo 'vm.vfs_cache_pressure=50' | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

Essential commands for swap management:

# View current usage
free -h
# Detailed swap info
sudo swapon --show
# Identify memory hogs
sudo smem -s swap -r

For systems running containerized workloads (Docker/LXD):

# Better to limit container memory than rely on swap
docker run -m 512m --memory-swap=1g my-container