Linux Services

The portreserve program aims to help services with well-known ports that lie in the portmap range. It prevents portmap from a real service's port by occupying it itself, until the real service tells it to release the port (generally in the init script). For example the cups package provides /etc/portreserve/cups. # cat /etc/portreserve/cups ipp In /etc/services, it is defined "service-name ipp" is equal to 631 ports. When portreserve service starts, portreserve reserves 631 ports. # … [Read more...] about Linux OS Service ‘portreserve’

Service Name kudzu Description This executes kudzu, the automatic hardware detection tool developed by Red Hat. "kudzu" detects and configures new and/or changed hardware on a system. It loads the required drivers and unloads redundant drivers. It is configured by default to run at system boot time to determine what hardware has been added or removed from the system. First, it compares hardware detected against information in /etc/sysconfig/hwconf (if it exists). Then it determines … [Read more...] about Linux OS Service ‘kudzu’

Service Name lm_sensors Description The lm_sensors is a service, set up to monitor hardware like CPU temperature or fan speed. Not all system hardware provides the necessary sensor hardware resource for the lm_sensors service to be useful. Later lm_sensor packages include the sensors_detect utility, which can be used to probe which sensors your hardware provides and which drivers you need. lm_sensors drivers include two groups: Bus drivers are provided for the I2C(Inter … [Read more...] about Linux OS Service ‘lm_sensors’

SELinux (Security Enhanced Linux) provides mandatory access control to the Linux operating system. SELinux is quite pervasive, even if only in PERMISSIVE mode. This can expose latent bugs in non-SELinux components that are not visible unless SELinux is running. Frustrated users have developed the perception that SELinux is difficult to use. The setroubleshoot service is intended to make SELinux more friendly. It collects SELinux audit events from the kernel and runs a series of analysis … [Read more...] about Linux OS Service ‘setroubleshoot’

The psacct service is responsible for starting and stopping process accounting at system boot time and at system shutdown. This service is a wrapper that invokes the action accounting control program. Service Control To obtain the psacct service, install the psacct RPM package: # yum install psacct To manage the psacct service for automated service start and stop, use the chkconfig tool: # chkconfig psacct on # chkconfig --list psacct psacct 0:off 1:off 2:on 3:on 4:on 5:on 6:off # … [Read more...] about Linux OS Service ‘psacct’

The NetworkManager daemon attempts to keep an active network connection available at all times. The NetworkManager facility offers a tool called NetworkManagerDispatcher which executes commands in /etc/NetworkManager/dispatcher.d according to the changing state of the network interfaces. All scripts in this directory are invoked for every state change of any network interface; the scripts must decide whether to process the event. The companion service NetworkManager must be running to … [Read more...] about Linux OS Service ‘NetworkManagerDispatcher’

The yum-updatesd daemon regularly checks the yum repository and provides notification of updates available for your system. Notifications can be made via syslog, email or dbus, a communication method used between applications. When configured to connect a yum repository, the daemon calls the "yum update" command to update packages on the system. The yum-updatesd service (/etc/init.d/yum-updatesd) is provided by the yum-updatesd package. When started, the service calls /usr/sbin/yum-updatesd, a … [Read more...] about Linux OS Service ‘yum-updatesd’

The acpid daemon supports the Advanced Configuration and Power Interface (ACPI) to allow intelligent power management on your system and to query battery and configuration status. It listens on a file (/proc/acpi/event) and when an event occurs, executes programs to handle the event. Rules are defined by simple configuration files. acpid will look in a configuration directory (/etc/acpi/events by default), and parse all files that do not begin with a period ('.'). Each file must define two … [Read more...] about Linux OS Service ‘acpid’

This executes rpcidmapd, with NFS service. The rpcidmapd maps usernames to UID and GID numbers. Service Control To manage the rpcidmapd service on demand, use the service tool or run the /etc/init.d/rpcidmapd script directly: # /sbin/service rpcidmapd Usage: /etc/init.d/rpcidmapd {start|stop|restart|condstart|condrestart|status} # /etc/init.d/rpcidmapd Usage: /etc/init.d/rpcidmapd {start|stop|restart|condstart|condrestart|status} The available commands are: CommandDescription … [Read more...] about Linux OS Service ‘rpcidmapd’

The avahi-daemon Linux service runs on client machines to perform network-based Zeroconf service discovery. Avahi is an implementation of the DNS Service Discovery and Multicast DNS specifications for Zeroconf Networking. User applications receive notice of discovered network services and resources using the Linux D-Bus message passing. The daemon coordinates application efforts in caching replies, helping minimize network traffic. Avahi provides a set of language bindings, including Python … [Read more...] about Linux OS Service ‘avahi-daemon’