How to Enable Swap Memory on Linux

If your system shows Swap: 0B 0B 0B, it means there is no active swap space. Follow these steps to check and enable swap.

1️⃣ Check If a Swap Partition Exists

Run:

lsblk | grep swap

If no output appears, you don't have a swap partition.

2️⃣ Check If Swap Is Configured in /etc/fstab

Run:

cat /etc/fstab | grep swap

If there is no output, swap is not set up.

3️⃣ Create a Swap File (If No Swap Exists)

If there is no swap partition, create a swap file manually:

Step 1: Create a 2GB Swap File

sudo fallocate -l 2G /swapfile  # Create a 2GB swap file
sudo chmod 600 /swapfile        # Secure it
sudo mkswap /swapfile           # Format as swap
sudo swapon /swapfile           # Enable swap

Step 2: Verify Swap is Active

free -mh
swapon --show

Step 3: Make Swap Persistent

To make the swap file persist after reboot, add this line to /etc/fstab:

/swapfile none swap sw 0 0

4️⃣ If You Have a Swap Partition, Enable It

If lsblk shows a swap partition (e.g., /dev/sdX), activate it with:

sudo swapon /dev/sdX  # Replace /dev/sdX with the actual partition name

5️⃣ Disable Swap Temporarily (Optional)

If you need to disable swap for a while, use:

sudo swapoff -a

To re-enable it:

sudo swapon -a

Now your system should have active swap memory! 🚀

Written by A.M. Rinas