How to remove a swap file in Linux

Swap space in Linux acts as overflow for physical RAM, providing additional virtual memory when running many processes or memory‑intensive workloads. A swap file created on an existing filesystem avoids repartitioning disks and can be convenient on virtual machines or cloud instances. When that swap file is no longer required, removing it frees disk space and simplifies resource planning.

The kernel’s virtual memory subsystem moves less frequently used pages from RAM into swap space, which may live on a dedicated partition or on a regular file marked and activated as swap. Swap files are typically referenced in /etc/fstab so they are enabled automatically at boot with swapon. Cleaning up a swap file requires deactivating it at runtime and removing any persistent configuration so it is not silently recreated.

Disabling a swap file on a system with limited RAM can increase the risk of out‑of‑memory conditions under heavy load, causing processes to be killed or the system to become unresponsive. Checking current memory and swap usage before proceeding reduces the chance of surprising failures. Safe removal assumes shell access with sudo privileges and applies only to swap files, not to swap partitions, which must be handled with different steps.

1. Open a terminal with sudo privileges.

   $ whoami
   root
   $ groups
   root

   Being in the sudo group or an equivalent administrative group allows privileged commands required for swap management.

2. List active swap areas to identify the swap file path.

   $ swapon --show
   NAME               TYPE  SIZE USED PRIO
   /var/lib/swap      file 1024M   0B   -2
   /mnt/data/swapfile file   64M   0B   -3

   The NAME column lists each active swap device or file and shows whether a swap file such as /mnt/data/swapfile is in use.

3. Check current memory and swap usage to evaluate whether disabling the swap file is safe.

   $ free -h
                  total        used        free      shared  buff/cache   available
   Mem:            23Gi       1.3Gi        20Gi        13Mi       1.6Gi        21Gi
   Swap:          1.1Gi          0B       1.1Gi

   High Swap usage under normal load can indicate that removing the swap file may cause out‑of‑memory conditions and process termination.

4. Disable the swap file so it is no longer used by the kernel.

   $ sudo swapoff /mnt/data/swapfile

   The command returns no output when the swap file is successfully deactivated.

5. Confirm that the swap file is no longer reported as active.

   $ swapon --show
   NAME          TYPE  SIZE USED PRIO
   /var/lib/swap file 1024M   0B   -2

   On systems with multiple swap areas, ensure the swap file path disappears from the list.

6. Remove the persistent swap entry from /etc/fstab.

   $ grep swapfile /etc/fstab
   2:/mnt/data/swapfile none swap sw 0 0
   $ sudo sed -i "/\\/mnt\\/data\\/swapfile none swap sw 0 0/d" /etc/fstab

   Editing with sed or a text editor achieves the same result; the key is to delete the line referencing the swap file.

7. Delete the swap file and its backing loop mount.

   $ sudo rm /mnt/data/swapfile
   $ sudo umount /mnt/data
   $ sudo losetup -d /dev/loop0
   $ sudo rm /root/sg-work/swapfs.img

   Confirm the paths carefully before removing files or detaching loop devices to avoid deleting unrelated data.

8. Verify that the swap file is no longer active or configured.

   $ swapon --show
   NAME          TYPE  SIZE USED PRIO
   /var/lib/swap file 1024M   0B   -2
   $ grep swapfile /etc/fstab

   Absence of the swap file path in both commands confirms that the swap file has been fully removed from runtime state and persistent configuration.