How to Turn Swap Off in Linux and Disable It Permanently

Updated: 18 October 2026 · Applies to: util-linux 2.41 and systemd 257 on Debian 13 (tested on a real Linux 6.12 kernel), zram-generator 1.2 (Fedora 44 default); the same steps work on Ubuntu 24.04 and 26.04, AlmaLinux and Rocky Linux 9 and 10

To turn swap off in Linux, run sudo swapoff -a. That lasts until the next reboot. To disable swap permanently, also put a # in front of every swap line in /etc/fstab and run sudo systemctl daemon-reload; on Fedora, also switch off the compressed swap in RAM (zram). swapon --show printing nothing means no swap is active.

Think before you do it. Without swap, the kernel's out-of-memory (OOM) killer ends a process as soon as RAM runs out, often the largest one, such as your database. On a VPS with little RAM, swap is the buffer that keeps a short peak from becoming an outage. A common reason to switch it off anyway: according to the Kubernetes documentation, the kubelet does not start on a Linux node with swap enabled unless it is configured for swap. If the server only swaps too eagerly, lower swappiness instead (step 7). More: What Is the Linux OOM Killer and How to Prevent It.

1. See which swap is active

$ swapon --show
NAME               TYPE      SIZE USED PRIO
/dev/ubdb          partition 256M   0B   -2
/mnt/data/swapfile file      256M   0B   -3
$ free -h
               total        used        free      shared  buff/cache   available
Mem:           302Mi        23Mi        18Mi          0B       268Mi       278Mi
Swap:          511Mi          0B       511Mi

(Lab example with a swap partition on the test disk /dev/ubdb and a swap file.) A swap partition or LVM volume shows as partition, a swap file as file. Compressed swap in RAM appears as /dev/zram0 with priority 100. To see which programs use swap, see How to Check Swap Usage in Linux and Find What Uses It.

2. Turn swap off now

sudo swapoff -a                 # all swap areas
sudo swapoff -v /swap.img       # only one, prints "swapoff /swap.img"

Everything in swap has to move back into RAM first, so check free -h before: available memory must be clearly larger than swap used. In our lab, programs had 118 MiB in swap and only 8 MiB of RAM was available. swapoff -a ended with Killed; the kernel log showed Out of memory: Killed process 801 (swapoff). The programs survived, but the swap partition stayed on. Free memory first, or add RAM, then try again. Emptying swap without turning it off is covered in How to Free Up Linux Memory: Clear Cache, Buffer, and Swap Safely.

3. Keep swap off after a reboot: /etc/fstab

1. Open /etc/fstab and put a # in front of every line with swap in the third column, for example:

   #/dev/mapper/almalinux-swap  none  swap  defaults  0 0
   #/swap.img                   none  swap  sw        0 0
   #UUID=598f7f9a-47a1-4d3f-a50e-2eabdcba59ed none swap sw 0 0

   The Ubuntu Server installer normally creates the swap file /swap.img; AlmaLinux and Rocky Linux often have an LVM swap volume.
2. Run sudo systemctl daemon-reload. systemd turns each fstab swap line into a unit (Loaded: loaded (/etc/fstab; generated)), and the reload removes the unit for a commented line.
3. Reboot when convenient and check:

   $ swapon --show
   $ systemctl list-units --type swap --all
     UNIT LOAD ACTIVE SUB DESCRIPTION
   
   0 loaded units listed.

4. Mask the swap unit

Masking stops systemd from ever starting a swap unit, even when the fstab line is still there. Find the unit name first; units are named after the device, so the lab disk /dev/ubdb gives dev-ubdb.swap and /dev/sda2 would give dev-sda2.swap:

$ systemctl list-units --type swap
  UNIT           LOAD   ACTIVE SUB    DESCRIPTION
  dev-ubdb.swap  loaded active active /dev/ubdb
  dev-zram0.swap loaded active active Compressed Swap on /dev/zram0
$ systemd-escape -p --suffix=swap /dev/mapper/almalinux-swap
dev-mapper-almalinux\x2dswap.swap

Stop the unit before you mask it. In our test, systemctl mask --now created the mask and then failed with Failed deactivating swap dev-ubdb.swap., leaving swap on until the reboot. This order worked:

$ sudo systemctl stop dev-ubdb.swap
$ sudo systemctl mask dev-ubdb.swap
Created symlink '/etc/systemd/system/dev-ubdb.swap' → '/dev/null'.

After the reboot the swap stayed off and systemctl status showed Loaded: masked. Keep the quotes around names that contain a backslash, for example sudo systemctl mask 'dev-mapper-almalinux\x2dswap.swap'. Undo with systemctl unmask.

5. Fedora and other systems with zram

Fedora installs zram-generator-defaults as part of its core package group. Its file /usr/lib/systemd/zram-generator.conf creates /dev/zram0, a compressed swap device in RAM, with zram-size = min(ram, 8192). Ubuntu 24.04 and 26.04 and Debian 13 do not enable zram unless you install a zram package such as systemd-zram-generator or zram-tools.

1. Turn it off now: sudo systemctl stop systemd-zram-setup@zram0.service (this also deactivates dev-zram0.swap).
2. Keep it off: override the vendor file with an empty one, sudo touch /etc/systemd/zram-generator.conf (as Fedora's file suggests), or with a link to /dev/null, sudo ln -s /dev/null /etc/systemd/zram-generator.conf (the zram-generator manual's way), or remove the package with sudo dnf remove zram-generator-defaults. In our test, the empty file, the /dev/null link and sudo systemctl mask systemd-zram-setup@zram0.service each kept zram off after a reboot. The kernel parameter systemd.zram=0 also stops the generator.

6. Remove the swap file or swap volume

Once swap is off and the fstab line is commented out, a swap file can be deleted to free the disk space: sudo rm /swap.img.

An LVM swap volume on AlmaLinux, Rocky Linux or RHEL is often named on the kernel command line. Red Hat's documentation shows resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap; check yours with cat /proc/cmdline. Before you delete the volume, remove only the swap parameters (never the root one), then the volume:

sudo grubby --update-kernel=ALL --remove-args="resume=/dev/mapper/almalinux-swap rd.lvm.lv=almalinux/swap"
sudo lvremove /dev/almalinux/swap

Use the exact names from your own command line, and remove them from GRUB_CMDLINE_LINUX in /etc/default/grub too if they appear there.

7. Swap less instead of never

echo "vm.swappiness = 10" | sudo tee /etc/sysctl.d/90-swappiness.conf
sudo sysctl --system

The default is 60 (also in our lab). A lower value makes the kernel prefer dropping file cache over swapping out programs, and swap stays available as a safety net for rare peaks. To size swap, see How Much Swap Should You Use in Linux.

Official documentation: swapon and swapoff, systemd.swap and zram-generator.conf.