Tested in ubuntu 18 / debian 9
Usually you can disable the swap by this command:
~ $ swapoff -a
And then comment entry swap line in /etc/fstab file for making reboot persistent. But sometimes in systems with systemd this is not enough, steps would be these:
Get the swap service name in use:
~ $ systemctl --type swap UNIT LOAD ACTIVE SUB DESCRIPTION dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap loaded active active /dev/mapper/ubuntu--vg-swap_1 LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, values depend on unit type. 1 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'.
Stop service, note “‘” on start and end in service name:
~ $ systemctl stop 'dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap'
Mask service:
~ $ systemctl mask 'dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap' Created symlink /etc/systemd/system/dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap → /dev/null.
Finally check service:
~ $ systemctl --type swap 0 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'.
If you want enable swap again:
~ $ systemctl unmask 'dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap' ~ $ systemctl start 'dev-mapper-ubuntu\x2d\x2dvg\x2dswap_1.swap'