NAME
systemd.swap - Swap unit configuration
SYNOPSIS
swap.swap
DESCRIPTION
A unit configuration file whose name ends in ".swap" encodes information about a swap device or file for memory paging controlled and supervised by systemd.
This man page lists the configuration options specific to this unit type. See systemd.unit(5) for the common options of all unit configuration files. The common configuration items are configured in the generic [Unit] and [Install] sections. The swap specific configuration options are configured in the [Swap] section.
Additional options are listed in systemd.exec(5), which define the execution environment the swapon(8) program is executed in, in systemd.kill(5), which define the way these processes are terminated, and in systemd.resource-control(5), which configure resource control settings for these processes of the unit.
Swap units must be named after the devices or files they control. Example: the swap device /dev/sda5 must be configured in a unit file dev-sda5.swap. For details about the escaping logic used to convert a file system path to a unit name, see systemd.unit(5). Note that swap units cannot be templated, nor is possible to add multiple names to a swap unit by creating additional symlinks to it.
Note that swap support on Linux is privileged, swap units are hence only available in the system service manager (and root's user service manager), but not in unprivileged user's service manager.
AUTOMATIC DEPENDENCIES
Implicit Dependencies
The following dependencies are implicitly added:
Additional implicit dependencies may be added as result of execution and resource control parameters as documented in systemd.exec(5) and systemd.resource-control(5).
Default Dependencies
The following dependencies are added unless DefaultDependencies=no is set:
FSTAB
Swap units may either be configured via unit files, or via /etc/fstab (see fstab(5) for details). Swaps listed in /etc/fstab will be converted into native units dynamically at boot and when the configuration of the system manager is reloaded. See systemd-fstab-generator(8) for details about the conversion.
If a swap device or file is configured in both /etc/fstab and a unit file, the configuration in the latter takes precedence.
When reading /etc/fstab, a few special options are understood by systemd which influence how dependencies are created for swap units.
noauto, auto
Added in version 218.
nofail
Added in version 218.
x-systemd.device-timeout=
Note that this option can only be used in /etc/fstab, and will be ignored when part of the Options= setting in a unit file.
Added in version 215.
x-systemd.makefs
Note that this option can only be used in /etc/fstab, and will be ignored when part of the Options= setting in a unit file.
See [email protected](8) and the discussion of wipefs(8) in systemd.mount(5).
Added in version 240.
OPTIONS
Swap unit files may include [Unit] and [Install] sections, which are described in systemd.unit(5).
Swap unit files must include a [Swap] section, which carries information about the swap device it supervises. A number of options that may be used in this section are shared with other unit types. These options are documented in systemd.exec(5), systemd.kill(5) and systemd.resource-control(5). The options specific to the [Swap] section of swap units are the following:
What=
Priority=
Options=
Added in version 217.
TimeoutSec=
Check systemd.unit(5), systemd.exec(5), and systemd.kill(5) for more settings.
SEE ALSO
systemd(1), systemctl(1), systemd-system.conf(5), systemd.unit(5), systemd.exec(5), systemd.kill(5), systemd.resource-control(5), systemd.device(5), systemd.mount(5), swapon(8), systemd-fstab-generator(8), systemd.directives(7)