'\" te
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.\" the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH SMF 7 "Jul 6, 2009"
.SH NAME
smf \- service management facility
.SH DESCRIPTION
.sp
.LP
The Solaris service management facility defines a programming model for
providing persistently running applications called \fIservices\fR. The facility
also provides the infrastructure in which to run services. A service can
represent a running application, the software state of a device, or a set of
other services. Services are represented in the framework by \fIservice
instance\fR objects, which are children of service objects. Instance objects
can inherit or override the configuration of the parent service object, which
allows multiple service instances to share configuration information. All
service and instance objects are contained in a \fIscope\fR that represents a
collection of configuration information. The configuration of the local Solaris
instance is called the "localhost" scope, and is the only currently supported
scope.
.sp
.LP
Each service instance is named with a fault management resource identifier
(FMRI) with the scheme \fBsvc:\fR. For example, the \fBsyslogd\fR(8) daemon
started at system startup is the default service instance named:
.sp
.in +2
.nf
svc://localhost/system/system-log:default
svc:/system/system-log:default
system/system-log:default
.fi
.in -2

.sp
.LP
Many commands also allow FMRI abbreviations. See the \fBsvcs\fR(1) man page for
one such example.
.sp
.LP
In the above example, 'default' is the name of the instance
and 'system/system-log' is the service name. Service names can comprise multiple
components separated by slashes (/). All components, except the last, compose
the \fIcategory\fR of the service. Site-specific services should be named with
a category beginning with 'site'.
.sp
.LP
A service instance is either enabled or disabled. All services can be enabled
or disabled with the \fBsvcadm\fR(8) command.
.sp
.LP
The list of managed service instances on a system can be displayed with the
\fBsvcs\fR(1) command.
.SS "Dependencies"
.sp
.LP
Service instances can have dependencies on a set of \fBentities\fR which can
include services and files. Dependencies govern when the service is started and
automatically stopped. When the dependencies of an enabled service are not
satisfied, the service is kept in the offline state. When its dependencies are
satisfied, the service is started. If the start is successful, the service is
transitioned to the online state.
.sp
.LP
Whether a dependency is satisfied is determined by its \fBgrouping\fR:
.sp
.ne 2
.na
\fB\fBrequire_all\fR\fR
.ad
.RS 16n
Satisfied when all cited services are running (online or degraded), or when all
indicated files are present.
.RE

.sp
.ne 2
.na
\fB\fBrequire_any\fR\fR
.ad
.RS 16n
Satisfied when one of the cited services is running (online or degraded), or
when at least one of the indicated files is present.
.RE

.sp
.ne 2
.na
\fB\fBoptional_all\fR\fR
.ad
.RS 16n
Satisfied if the cited services are running (online or degraded) or do not run
without administrative action (disabled, maintenance, not present, or offline
waiting for dependencies which do not start without administrative action).
.RE

.sp
.ne 2
.na
\fB\fBexclude_all\fR\fR
.ad
.RS 16n
Satisfied when all of the cited services are disabled, in the maintenance
state, or when cited services or files are not present.
.RE

.sp
.LP
Once running (online or degraded), if a service cited by a \fBrequire_all\fR,
\fBrequire_any\fR, or \fBoptional_all\fR dependency is stopped or refreshed,
the SMF considers why the service was stopped and the \fBrestart_on\fR
attribute of the dependency to decide whether to stop the service.
.sp
.in +2
.nf
                   |  restart_on value
event              |  none  error restart refresh
-------------------+------------------------------
stop due to error  |  no    yes   yes     yes
non-error stop     |  no    no    yes     yes
refresh            |  no    no    no      yes
.fi
.in -2

.sp
.LP
A service is considered to have stopped due to an error if the service has
encountered a hardware error or a software error such as a core dump. For
\fBexclude_all\fR dependencies, the service is stopped if the cited service is
started and the \fBrestart_on\fR attribute is not \fBnone\fR.
.sp
.LP
The dependencies on a service can be listed with \fBsvcs\fR(1)\ or
\fBsvccfg\fR(8), and modified with \fBsvccfg\fR(8).
.SS "Restarters"
.sp
.LP
Each service is managed by a restarter. The master restarter,
\fBsvc.startd\fR(8) manages states for the entire set of service instances and
their dependencies. The master restarter acts on behalf of its services and on
delegated restarters that can provide specific execution environments for
certain application classes. For instance, \fBinetd\fR(8) is a delegated
restarter that provides its service instances with an initial environment
composed of a network connection as input and output file descriptors. Each
instance delegated to \fBinetd\fR(8) is in the online state. While the daemon
of a particular instance might not be running, the instance is available to
run.
.sp
.LP
As dependencies are satisfied when instances move to the online state,
\fBsvc.startd\fR(8) invokes start methods of other instances or directs the
delegated restarter to do so. These operations might overlap.
.sp
.LP
The current set of services and associated restarters can be examined using
\fBsvcs\fR(1). A description of the common configuration used by all restarters
is given in \fBsmf_restarter\fR(7).
.SS "Methods"
.sp
.LP
Each service or service instance must define a set of methods that start, stop,
and, optionally, refresh the service. See \fBsmf_method\fR(7) for a more
complete description of the method conventions for \fBsvc.startd\fR(8) and
similar \fBfork\fR(2)-\fBexec\fR(2) restarters.
.sp
.LP
Administrative methods, such as for the capture of legacy configuration
information into the repository, are discussed on the \fBsvccfg\fR(8) manual
page.
.sp
.LP
The methods for a service can be listed and modified using the \fBsvccfg\fR(8)
command.
.SS "States"
.sp
.LP
Each service instance is always in a well-defined state based on its
dependencies, the results of the execution of its methods, and its potential
contracts events. The following states are defined:
.sp
.ne 2
.na
\fB\fBUNINITIALIZED\fR\fR
.ad
.RS 17n
This is the initial state for all service instances. Instances are moved to
maintenance, offline, or a disabled state upon evaluation by
\fBsvc.startd\fR(8) or the appropriate restarter.
.RE

.sp
.ne 2
.na
\fB\fBOFFLINE\fR\fR
.ad
.RS 17n
The instance is enabled, but not yet running or available to run. If restarter
execution of the service start method or the equivalent method is successful,
the instance moves to the online state. Failures might lead to a degraded or
maintenance state. Administrative action can lead to the uninitialized state.
.RE

.sp
.ne 2
.na
\fB\fBONLINE\fR\fR
.ad
.RS 17n
The instance is enabled and running or is available to run. The specific nature
of the online state is application-model specific and is defined by the
restarter responsible for the service instance. Online is the expected
operating state for a properly configured service with all dependencies
satisfied. Failures of the instance can lead to a degraded or maintenance
state. Failures of services on which the instance depends can lead to offline
or degraded states.
.RE

.sp
.ne 2
.na
\fB\fBDEGRADED\fR\fR
.ad
.RS 17n
The instance is enabled and running or available to run. The instance, however,
is functioning at a limited capacity in comparison to normal operation.
Failures of the instance can lead to the maintenance state. Failures of
services on which the instance depends can lead to offline or degraded states.
Restoration of capacity should result in a transition to the online state.
.RE

.sp
.ne 2
.na
\fB\fBMAINTENANCE\fR\fR
.ad
.RS 17n
The instance is enabled, but not able to run. Administrative action (through
\fBsvcadm clear\fR) is required to move the instance out of the maintenance
state. The maintenance state might be a temporarily reached state if an
administrative operation is underway.
.RE

.sp
.ne 2
.na
\fB\fBDISABLED\fR\fR
.ad
.RS 17n
The instance is disabled. Enabling the service results in a transition to the
offline state and eventually to the online state with all dependencies
satisfied.
.RE

.sp
.ne 2
.na
\fB\fBLEGACY-RUN\fR\fR
.ad
.RS 17n
This state represents a legacy instance that is not managed by the service
management facility. Instances in this state have been started at some point,
but might or might not be running. Instances can only be observed using the
facility and are not transferred into other states.
.RE

.sp
.LP
States can also have transitions that result in a return to the originating
state.
.SS "Properties and Property Groups"
.sp
.LP
The dependencies, methods, delegated restarter, and instance state mentioned
above are represented as properties or property groups of the service or
service instance. A service or service instance has an arbitrary number of
property groups in which to store application data. Using property groups in
this way allows the configuration of the application to derive the attributes
that the repository provides for all data in the facility. The application can
also use the appropriate subset of the \fBservice_bundle\fR(5) DTD to represent
its configuration data within the framework.
.sp
.LP
Property lookups are composed. If a property group-property combination is not
found on the service instance, most commands and the high-level interfaces of
\fBlibscf\fR(3LIB) search for the same property group-property combination on
the service that contains that instance. This allows common configuration among
service instances to be shared. Composition can be viewed as an inheritance
relationship between the service instance and its parent service.
.sp
.LP
Properties are protected from modification by unauthorized processes. See
\fBsmf_security\fR(7).
.SS "General Property Group"
.sp
.LP
The \fBgeneral\fR property group applies to all service instances. It includes
the following properties:
.sp
.ne 2
.na
\fBenabled (boolean)\fR
.ad
.RS 21n
Specifies whether the instance is enabled. If this property is not present on
an instance, SMF does not tell the instance's restarter about the existence of
the restarter.
.RE

.sp
.ne 2
.na
\fBrestarter (fmri)\fR
.ad
.RS 21n
The restarter for this service. See the Restarters section for more
information. If this property is unset, the default system restarter is used.
.RE

.SS "Snapshots"
.sp
.LP
Historical data about each instance in the repository is maintained by the
service management facility. This data is made available as read-only snapshots
for administrative inspection and rollback. The following set of snapshot types
might be available:
.sp
.ne 2
.na
\fB\fBinitial\fR\fR
.ad
.RS 15n
Initial configuration of the instance created by the administrator or produced
during package installation.
.RE

.sp
.ne 2
.na
\fB\fBlast_import\fR\fR
.ad
.RS 15n
Configuration as prescribed by the manifest of the service that is taken during
\fBsvccfg\fR(8) import operation. This snapshot provides a baseline for
determining property customization.
.RE

.sp
.ne 2
.na
\fB\fBprevious\fR\fR
.ad
.RS 15n
Current configuration captured when an administrative undo operation is
performed.
.RE

.sp
.ne 2
.na
\fB\fBrunning\fR\fR
.ad
.RS 15n
The running configuration of the instance.
.RE

.sp
.ne 2
.na
\fB\fBstart\fR\fR
.ad
.RS 15n
Configuration captured during a successful transition to the online state.
.RE

.sp
.LP
The \fBsvccfg\fR(8) command can be used to interact with snapshots.
.SS "Special Property Groups"
.sp
.LP
Some property groups are marked as "non-persistent". These groups are not
backed up in snapshots and their content is cleared during system boot. Such
groups generally hold an active program state which does not need to survive
system restart.
.SS "Configuration Repository"
.sp
.LP
The current state of each service instance, as well as the properties
associated with services and service instances, is stored in a system
repository managed by \fBsvc.configd\fR(8). This repository is transactional
and able to provide previous versions of properties and property groups
associated with each service or service instance.
.sp
.LP
The repository for service management facility data is managed by
\fBsvc.configd\fR(8).
.SS "Service Bundles, Manifests, and Profiles"
.sp
.LP
The information associated with a service or service instance that is stored in
the configuration repository can be exported as XML-based files. Such XML
files, known as service bundles, are portable and suitable for backup purposes.
Service bundles are classified as one of the following types:
.sp
.ne 2
.na
\fB\fBmanifests\fR\fR
.ad
.RS 13n
Files that contain the complete set of properties associated with a specific
set of services or service instances.
.RE

.sp
.ne 2
.na
\fB\fBprofiles\fR\fR
.ad
.RS 13n
Files that contain a set of service instances and values for the enabled
property (type \fBboolean\fR in the general property group) on each instance.
.sp
Profiles can also contain configuration values for properties in services and
instances. Template elements cannot be defined in a profile.
.RE

.sp
.LP
Service bundles can be imported or exported from a repository using the
\fBsvccfg\fR(8) command. See \fBservice_bundle\fR(5) for a description of the
service bundle file format with guidelines for authoring service bundles.
.sp
.LP
A \fIservice archive\fR is an XML file that contains the description and
persistent properties of every service in the repository, excluding transient
properties such as service state. This service archive is basically a 'svccfg
export' for every service which is not limited to named services.
.SS "Milestones"
.sp
.LP
An \fBsmf\fR milestone is a service that aggregates a multiple service
dependencies. Usually, a milestone does nothing useful itself, but declares a
specific state of system-readiness on which other services can depend. One
example is the \fBname-services\fR milestone, which simply depends upon the
currently enabled name services.
.SS "Legacy Startup Scripts"
.sp
.LP
Startup programs in the \fB/etc/rc?.d\fR directories are executed as part of
the corresponding run-level milestone:
.sp
.ne 2
.na
\fB\fB/etc/rcS.d\fR\fR
.ad
.RS 14n
milestone/single-user:default
.RE

.sp
.ne 2
.na
\fB\fB/etc/rc2.d\fR\fR
.ad
.RS 14n
milestone/multi-user:default
.RE

.sp
.ne 2
.na
\fB\fB/etc/rc3.d\fR\fR
.ad
.RS 14n
milestone/multi-user-server:default
.RE

.sp
.LP
Execution of each program is represented as a reduced-functionality service
instance named by the program's path. These instances are held in a special
legacy-run state.
.sp
.LP
These instances do not have an enabled property (type \fBboolean\fR in the
general property group) and, generally, cannot be manipulated with the
\fBsvcadm\fR(8) command. No error diagnosis or restart is done for these
programs.
.SH SEE ALSO
.sp
.LP
.BR svcs (1),
.BR exec (2),
.BR fork (2),
.BR strftime (3C),
.BR libscf (3LIB),
.BR contract (5),
.BR service_bundle (5),
.BR smf_bootstrap (7),
.BR smf_method (7),
.BR smf_restarter (7),
.BR smf_security (7),
.BR inetd (8),
.BR svc.configd (8),
.BR svc.startd (8),
.BR svcadm (8),
.BR svccfg (8)