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== Pronunciation ==
   {{{
 day'mn or dee'mn
~-[[DebianWiki/EditorGuide#translation|Translation(s)]]: English-~
----
A [[http://en.wikipedia.org/wiki/Daemon_(computing)|daemon]] is a background process, also known as a service, usually started during the initial boot sequence by [[init]]. Daemons typically run independent of users, waiting for events to occur and providing services. Some common daemons include:

 * sshd - listens for and manages incoming SSH connections
 * acpid - listens for power management events and triggers scripts based on them)
 * apache - provides a local HTTP web server

## If your page gets really long, uncomment this Table of Contents
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== Daemons under Debian ==
Debian makes use of [[http://en.wikipedia.org/wiki/Init#SysV-style|System V]]-style init scripts for daemon management, allowing daemons to run conditionally, based on the current RunLevel of the computer. For example, a daemon can be configured to run only when the computer is in single-user mode (runlevel 1) or, more commonly, when in multi-user mode (runlevels 2-5). For more information, see RunLevel.
 
== Debian daemon configuration ==
=== Start, stop and reload daemons ===
The easiest way to manually (and temporarily) start, stop or reload a daemon is the run the following in a console or terminal as root:
{{{
# /etc/init.d/daemonname [stop|start|restart]
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Controlling daemons in this manner is temporary and not survive a reboot. Refer to the next section to manage daemons on a more permanent basis.
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== What is a daemon? == === Enable/disable daemons ===
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From the mythological meaning, later rationalized as the acronym `Disk And Execution MONitor'.
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''various definitions can be fount on the web : ''
 * A program that is not invoked explicitly, but lies dormant waiting for some condition(s) to occur. The idea is that the perpetrator of the condition need not be aware that a daemon is lurking (though often a program will commit an action only because it knows that it will implicitly invoke a daemon). For example, under ITS writing a file on the LPT spooler's directory would invoke the spooling daemon, which would then print the file. The advantage is that programs wanting (in this example) files printed need neither compete for access to nor understand any idiosyncrasies of the LPT. They simply enter their implicit requests and let the daemon decide what to do with them. Daemons are usually spawned automatically by the system, and may either live forever or be regenerated at intervals. Daemon and demon are often used interchangeably, but seem to have distinct connotations. The term `daemon' was introduced to computing by CTSS people (who pronounced it ''dee'mon'') and used it to refer to what ITS called a dragon; the prototype was a program called DAEMON that automatically made tape backups of the file system. Although the meaning and the pronunciation have drifted, we think this glossary reflects current (2000) usage. From Jargon Dictionary
== See also ==
 * [[init]]
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 * A background process of the operating system that usually has root security level permission. A daemon usually lurks in the background until something triggers it into activity, such as a specific time or date, time interval, receipt of e-mail, etc. From I-gloss

 * A process lurking in the background, usually unnoticed, until something triggers it into action. For example, the \cmd{update} daemon wakes up every thirty seconds or so to flush the buffer cache, and the \cmd{sendmail} daemon awakes

 * A program that runs continuously in the background, until activated by a particular event. A daemon can constantly query for requests or await direct action from a user or other process. From Redhat-9-Glossary

 * A program which runs for an extended period (usually "forever") to handle requests for service as needed. From Linux Guide @FirstLinux

 * A program, usually on a computer running UNIX, that serves some obscure function (such as routing electronic mail to its recipients) and usually has a very limited user interface. There's some debate about the origins of the word, but most say it derives from the devilish spirits of Greek mythology. From QUECID

 * Disk And Execution MONitor (Unix) From VERA

 * Daemon (service) : On UNIX, a daemon is a program running in the background, usually providing some sort of service. Typical daemons are those that provide e-mail, printing, telnet, FTP, and web access. From Hacking-Lexicon

== List of service daemons ==

''' Note: This page is very incomplete'''

 * amd Auto Mount Daemon
 * [:CronAnacronAtBatchSchedulers:anacron] Executed delayed cron tasks at boot time
 * apmd Advanced Power Management Daemon
 * arpwatch watches for ethernet IP address pairings that are resolved using the ARP protocol
 * [:CronAnacronAtBatchSchedulers:atd] Runs jobs queued using the at tool
 * [:AutoFs:autofs] Supports the automounter daemon allowing mount and unmount of devices on demand
 * bincimapd
 * bootparmd A Internet Bootstrap Protocol server daemon
 * chttpd
 * [:CronAnacronAtBatchSchedulers:crond] Task Scheduler
 * [:DevFS:devfsd]
 * [:DHCP Server:dhcpd] Dynamic Host Configuration Protocol and Internet Bootstrap Protocol Server
 * drakfont A font server daemon used in Mandrake Linux
 * egpup
 * fetchmail daemon to retrieve mail from servers at regular intervals
 * ftpd FTP Server Daemon vsftpd
 * gated routing daemon that handles multiple routing protocols and replaces routed and egpup
 * gpm General Purpose Mouse Daemon
 * httpd Web Server Daemon
 * identd Provides the identity of a user of a particular TCP connection
 * inetd Internet Superserver Daemon
 * imapd bincimap
 * innd Usenet News Server Daemon
 * ipchains A packet forwarding / firewall daemon
 * isdn ISDN network interfacing server daemon
 * kapmd Advanced Power Management Daemon
 * kblockd
 * kerneld Automatically loads and unloads kernel modules
 * keventd
 * keytable Loads the appropriate keyboard map from the /etc/sysconfig/keyboard configuration file
 * kheader
 * klogd
 * ksoftirqd
 * kswapd
 * kswapd0
 * kudsu detects and configures new or changed hardware during boot
 * kupdated
 * linuxconf Startup hook for the linuxconf configuration system
 * lockd
 * lpd Line Printer Daemon
 * mathoptd A small single process httpd daemon with CGI support
 * mcserv Server for the midnight command networking filesystem
 * micro_httpd
 * mountd
 * mysql Database server daemon
 * named A DNS server daemon
 * netfs Network Filesystem Mounter
 * network Activates all network interfaces at boot time
 * nfsd
 * nfslock Used to start and stop nfs file locking services
 * nmbd
 * numlock This daemon locks the numlock key during a runlevel change
 * pcmcia Provides generic pcmcia services
 * portmap
 * [:Postfix:postfix] A mail transport agent used as a replacement for sendmail
 * [:PostgreSql:postgresql] Database server daemon
 * random Random number generating daemon
 * rlprd Remote line printer proxy daemon
 * routed Manages routing tables
 * rpciod Remote Procedure Call daemon
 * rquotad
 * rstatd kernel statistics server daemon
 * rusersd Allows users to find one another over the network
 * rwalld Allows users to write messages on remote terminals using rwall
 * rwhod maintains the database used by the rwho and ruptime tools
 * sendmail A mail transfer agent
 * samba
 * smbd Samba Server Daemon
 * smtpd Simple Mail Transfer Protocol Daemon
 * snmpd Simple Network Management Protocol Daemon
 * sound A sound server daemon
 * squid A web page caching proxy server daemon
 * sshd
 * statd
 * syslogd System logging daemon
 * tcpd Service wrapper to restrict access to inetd based services through hosts.allow and hosts.deny
 * telnetd Telnet Server daemon
 * uptimed Uptime logging daemon
 * usb Daemon to manage devices attached to the universal serial bus
 * vsftpd
 * walld
 * webmin Web based administration server daemon
 * xfs X font server daemon
 * xinetd Enhanced Internet Superserver Daemon
 * xntd Network Time Server Daemon
 * ypbind A bind server for Network Information Services
----
## If this page belongs to an existing Category, add it below.
## CategorySomething | CategoryAnother

Translation(s): English


A daemon is a background process, also known as a service, usually started during the initial boot sequence by ?init. Daemons typically run independent of users, waiting for events to occur and providing services. Some common daemons include:

  • sshd - listens for and manages incoming SSH connections
  • acpid - listens for power management events and triggers scripts based on them)
  • apache - provides a local HTTP web server

Daemons under Debian

Debian makes use of System V-style init scripts for daemon management, allowing daemons to run conditionally, based on the current RunLevel of the computer. For example, a daemon can be configured to run only when the computer is in single-user mode (runlevel 1) or, more commonly, when in multi-user mode (runlevels 2-5). For more information, see RunLevel.

Debian daemon configuration

Start, stop and reload daemons

The easiest way to manually (and temporarily) start, stop or reload a daemon is the run the following in a console or terminal as root:

# /etc/init.d/daemonname [stop|start|restart]

Controlling daemons in this manner is temporary and not survive a reboot. Refer to the next section to manage daemons on a more permanent basis.

Enable/disable daemons

See also

  • ?init