Basic SMF Commands¶
SMF consists of four command line utilities:
svcs: allows you to examine the state of your services and determine what went wrong.
svcadm: enable, disable, and restart a service.
svccfg: load manifest files (XML) that maintain configurations for each service.
svcprop: retrieves properties on a service (useful when writing custom scripts)
Examining Service Status - svcs¶
svcs command displays information about the state of your
services. This typically means whether or not they are running and any
problems encountered when attempting to start them. In general, services
will fall into three different states:
online: the service is enabled and functioning normally
offline: the service is stopped and disabled
maintenance: the service has encountered a problem and is on hold until the problem is addressed by an administrator.
svcs command with the
-a argument displays a list of all
online and offline services. By default
svcs prints out:
status: the current state of the service.
stime: when the service entered the current state.
FMRI: the name of the service.
Each service is identified by a Fault Management Resource Identifier (FMRI). For example, the FMRI for the Apache service is:
The above FMRI breaks down in the following way:
||The service type|
||The service name|
||The service instance|
For example, this output shows that Apache was disabled on May 31st:
$ svcs svc:/network/http:cswapache2 STATE STIME FMRI disabled May_31 svc:/network/http:cswapache2
An easy way of uncovering the FMRI for a service is by using
svcs -a. For example, using grep in the following
exposes the FMRI of the MySQL service, which is
$ svcs -a | grep -i mysql enabled May_31 svc:/network/cswmysql5:default
You ca n abbreviate an FMRI by specifying the instance name or the
trailing portion of the service name. For example, valid abbreviations
Starting and Stoping Services - svcadm¶
svcadm command is used to enable, disable, restart, or refresh
services. For example, this command enables the MySQL service.
sudo svcadm enable cswmysql5
svcs, you can verify that the service is enabled:
$ svcs cswmysql5 STATE STIME FMRI online 15:20:39 svc:/network/cswmysql5:default
disable to stop services. For example, this stops the MySQL
sudo svcadm disable cswmysql5
restart to refresh a service. For example, after making a
configuration change, you can refresh an enabled service like this:
sudo svcadm restart cswmysql5
Some daemons do not respond to the
restart command. If that is the
case, you will need to disable and re-enable the service.
Conducting Service Maintenance - svcadm clear¶
If a service enters maintenance mode or becomes disabled, you will need
to perform some maintenance before SMF can restart the service. This
means resolving any conflicts that prevent the service from running then
svcadm clear to clear the service state. When
svcadm clear, you need to specify the service FMRI.
This command does nothing to fix a service, it just signals that the service is ready to resume. Before you can clear a service state, you need to ensure that you resolve the conflict that caused the service to go into maintenance mode. For example, if you configure Postgres to use an IP port that is already in use by another service, the Postgres service will terminate abnormally and go into maintenance mode. In this case, you would need to resolve the IP conflict by modifying the Postgres configuration to use another IP or terminating the conflicting service. You would then clear the state after resolving the conflict.
Once the state is cleared, the service can resume. Each service has an
assigned service restarter agent that is responsible for carrying out
actions against it. The default service restarter is
- If a service instance is in maintenance mode, this command informs the restarter agent that the service was repaired.
- If a service instance is disabled, this command requests that the restarter agent transition the service to the online state.
For example, the following will clear the state of the Apache service and SMF will automatically restart the service once cleared:
sudo svcadm clear svc:/network/http:cswapache2
Verifying a Service is in Maintenance Mode¶
SMF will place a service in maintenance mode when the service encounters something that causes it to crash. This usually indicates an error with the service but can also occur if your SmartMachine is running out of resources (RAM or disk space).
To verify if a service is in maintenance mode:
Run this command:
This will show all running and disabled services. If a service is in maintenance mode, you will see something similar to this:
maintenence 18:50:25 svc:/network/webmin:webmin
Review the log to root-cause why the service was in maintenance mode.
- Take the service out of maintenance mode:
svcadm clear service_name
Verifying a Service is Disabled¶
To verify if a service is disabled:
If the service is disabled, you will see something similar to this:
disabled 18:51:10 svc:/network/webmin:webmin
Enabling a Service¶
To enable a service:
Enable the service:
svcadm enable service_name
Verify the service is enabled:
svcs -a | grep service_name
If successful, you should see something similar to this:
online 18:50:25 svc:/network/webmin:webmin
The term "online" is the service state and indicates that the service is running.
Examining Service Contracts -
SMF maintains a contract with every running service it manages. The
contract keeps track of what processes are running for any given
service. Using the
-p option, you can determine all the processes that
belong to a service. In the following example, the MySQL daemon is
process number 29004.
$ svcs -p network/cswmysql5 STATE STIME FMRI online 16:55:27 svc:/network/cswmysql5:default 16:55:27 28938 mysqld_safe 16:55:27 29004 mysqld
The following example demonstrates how SMF restarts a service when it stops unexpectedly:
$ kill -9 29004 $ svcs -p network/cswmysql5 STATE STIME FMRI online* 17:00:01 svc:/network/cswmysql5:default 16:55:27 28938 mysqld_safe 17:00:01 29228 mysqld $ mysql -u mysql ... mysql> \q Bye
Even though the MySQL daemon was unexpectedly terminated, it was automatically restarted by SMF. Notice that the STIME shows that the MySQL service is back online. The inclusion of an asterisk with the "online" state indicates that the service is currently in transition. However, the MySQL service is already back online by the time the next command is run.
SMF does not restart the service in brain-dead mode like a
inittab; You can configure a threshold for service restarts.
For example, numerous restarts of a service in a 60 second time frame
might indicate a severe issue in your environment. You can configure a
restart threshold in SMF for that service. At that point, SMF will put
the service in "maintenance" mode, and the service will remain in that
state until you clear it with
Configuring Services -
svccfg command allows you to import, export, and modify service
configurations. You specify entities to manipulate by using
-s option with an FMRI. The following example will set an
environment variable for the specified FMRI with the value you specify.
svccfg -s FMRI setenv ENV_VARIABLE value
You can invoke
svccfg directly with individual subcommands or by
specifying a script file.
If you make any changes to a service using this command, you need to restart the service for the changes to take effect.
Enabling SMF Access¶
If you want to enable users with no sudo access to manage SMF, you can modify a user profile with the following command:
usermod -P 'Service Management' myuser
After this change, the specified user is able to manage SMF (import,
stop, start) without access to
sudo. This minimizes the need for
unnecessarily sharing sudo access among users.
Checking properties of a service¶
To retrieve a specific setting for a service, we use svcprop in this case to figure out which ipf.conf ipfilter is using:
# svcprop -p firewall_config_default/custom_policy_file network/ipfilter :default /etc/ipf/ipf.conf
Uncovering Information About Services¶
Using SMF to uncover information about a service is easy.
||List all services for this SmartMachine, including disabled services.|
||List explanations for all services that are running but not enabled or services that are preventing another service from runn ing.|
||List all processes for the service you specify.|
- Ben Rockwood's SMF CheatSheet.