Index · Directives systemd 249

Name

systemd.slice — Slice unit configuration

Synopsis

slice.slice

Description

A unit configuration file whose name ends in ".slice" encodes information about a slice unit. A slice unit is a concept for hierarchically managing resources of a group of processes. This management is performed by creating a node in the Linux Control Group (cgroup) tree. Units that manage processes (primarily scope and service units) may be assigned to a specific slice. For each slice, certain resource limits may be set that apply to all processes of all units contained in that slice. Slices are organized hierarchically in a tree. The name of the slice encodes the location in the tree. The name consists of a dash-separated series of names, which describes the path to the slice from the root slice. The root slice is named -.slice. Example: foo-bar.slice is a slice that is located within foo.slice, which in turn is located in the root slice -.slice.

Note that slice units cannot be templated, nor is possible to add multiple names to a slice unit by creating additional symlinks to its unit file.

By default, service and scope units are placed in system.slice, virtual machines and containers registered with systemd-machined(8) are found in machine.slice, and user sessions handled by systemd-logind(8) in user.slice. See systemd.special(7) for more information.

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 slice specific configuration options are configured in the [Slice] section. Currently, only generic resource control settings as described in systemd.resource-control(5) are allowed.

See the New Control Group Interfaces for an introduction on how to make use of slice units from programs.

Automatic Dependencies

Implicit Dependencies

The following dependencies are implicitly added:

  • Slice units automatically gain dependencies of type After= and Requires= on their immediate parent slice unit.

Default Dependencies

The following dependencies are added unless DefaultDependencies=no is set:

  • Slice units will automatically have dependencies of type Conflicts= and Before= on shutdown.target. These ensure that slice units are removed prior to system shutdown. Only slice units involved with late system shutdown should disable DefaultDependencies= option.

See Also

systemd(1), systemd.unit(5), systemd.resource-control(5), systemd.service(5), systemd.scope(5), systemd.special(7), systemd.directives(7)