Centos Servisleri ve ne işe yaradıkları

acpid - off Advanced Configuration and Power Interface
       event daemon. Shutdown applications if the power fails.

          aep1000 - off AEP1000/AEP2000 coprocessor driver.

          anacron - off Cron-like, but doesn't assume that the
              machine is always on.

             apmd - off Advanced Power Management. Only on for your
       UPS to shutdown your computer when the power fails.

              atd - off Run jobs queued for later execution by "at".

           autofs - off Auto mount CDs and other file system-like
       devices and media.

          bcm5820 - off Hardware cryptographic accelerator support for
       the BCM5820 Cryptonet driver.

         cpuspeed - on for laptops, off for desktop computers.

            crond - on Runs regularly scheduled system tasks, e.g. a
                    task that runs once a day.

             cups - on Common Unix Printing System. Necesary if you
       want to print.

cups-config-daemon - off(?) Works with HAL to dynamically manage printer
                    configuration. Might overwrite
                    /etc/cups/cupsd.conf. See:
                    http://www.cups.org/articles.php?L301

         cxoffice - off Probably runs automatically if you have
                    Crossover Office and run an installed Windows application.

        dc_client - off Distributed session cache client proxy.

        dc_server - off Distributed session cache server.

              gpm - off unless you want mouse cut/paste on the
       non-graphical console.

        haldaemon - on Auto-recognizes various kinds of hardware and
       mountable media.

            httpd - off The Apache web server. Only on if you need a
       web server.

         iptables - on The firewall.

             irda - off Infrared wireless device daemon. For PDA, etc.

       irqbalance - on If you have a multiprocessor system. Off on
       all single cpu machines.

             isdn - off Only used if you have an ISDN network connection.
       kudzu - off Detects and configures new and/or changed
       hardware on a system. Can be run manually if you need it.

             lisa - off Scans your network to provide information
                    about hosts on your network, perhaps including
                    Windows shares. Some versions have security
                    problems. Part of kdenetwork utilities.

       lm_sensors - off Monitor system sensors such as CPU and
       motherboard temperature.

    mDNSResponder - off Publishes and browses available network
       services via Zeronconf (aka "Rendezvous").

        mdmonitor - off Part of the mdadm package to administer
                    software RAID. See rpm -qi mdadm

            mdmpd - off Monitor MD multipath devices, e.g. disks with
       more than one controller. Apparently only for
       RAID arrays.

       messagebus - on Provides a communication bus for dbus. Programs
                    talk to other programs. Probably leave enabled.

    microcode_ctl - on for Intel CPUs, off for AMD processors. Only works on Intel CPUs
                    (doesn't work with AMD). I'm not clear what the
                    updated microcode does. You can find out your cpu
                    info on Linux systems with this command:
       cat /proc/cpuinfo
       More info at:
                    http://www.urbanmyth.org/microcode/

           mysqld - off A crash prone, slow, non-standard SQL
       database server.

            named - off A DNS server.

          netdump - off Only for diagnosing kernel crashes.

            netfs - off Automatically Mounts and unmounts all Network
                    File System (NFS), SMB/CIFS (Lan
                    Manager/Windows), and NCP (NetWare) mount points.
                    This is the only thing you need if you are an NFS
                    client (e.g. not an NFS server), since netfs will
                    run any other necessary daemons. Netfs may
                    automatically handle everything necessary for the
                    other (non-NFS) protocols, but I've only tested
                    it with NFS. Disable this if you don't use NFS,
                    Samba, or NetWare.

         netplugd - off Automatic recognition of active/inactive
       network interfaces.

          network - on if you have an Ethernet connection. Off for
                    modem users.

              nfs - off Network File System. Only on to allows other
       unix systems to share your hard drive (volume, file system). Not
       necessary if you are a client to a shared volume.

          nfslock - off Provides NFS file locking functionality.
                    Disable if you aren't using NFS. Required by nfs.

             nifd - off Network interface monitor. Calls
       mDNSResponder if your IP address changes.

             nscd - off Nscd provides cacheing for the passwd(5),
       group(5), and hosts(5) databases.

             ntpd - off Network Time Protocol. Easier to put this in
       cron: /usr/sbin/ntpdate -s -u ntp1.virginia.edu

           pcmcia - on for laptop users with PCMCIA cards. Off for
       desktop machines.

          portmap - off Netfs will start portmap as necessary.
       Portmap is DARPA port to RPC program number
       mapper. Required if you are an nfs client or
       server (although netfs starts portmap for
       clients, so you don't need it explicitly
       enabled). If you're not using NFS or NIS, then
       you should disable portmap. Some (?) versions of
       portmap are highly insecure. You can run `rpcinfo
       -p $hostname` against your system to see what
       additional services it is providing.  More info
       at:
       http://cert.uni-stuttgart.de/archive/suse/security/2003/04/msg00141.html

       postgresql - off The most powerful, fastest, easiest to use SQL
       database. Robust and has excellent documentation.

           psacct - off Daemon used by several utilities for monitoring process
                    activities, including ac, lastcomm, accton, and sa.

        readahead - off The readahead process preloads the buffer
                    cache with files that might be paged in one 'page
                    demand triggered' read at a time.  This can speed
                    things up of boxes with enough memory. Config
                    file is: /etc/readahead.files

  readahead_early - off See readahead. Config file is: /etc/readahead.early.files

            rhnsd - off Queries the Red Hat Network for updates and
       information.

          rpcgssd - off Part of the nfs-utils package. Required by nfs.

        rpcidmapd - off Required if you are running an nfs server.

       rpcsvcgssd - off Required by nfs.

        saslauthd - off unless you are using plaintext SASL password
       authentication

         sendmail - off Part of the mail server. Only on if you
       machine is mail server.

          sgi_fam - off FAM is a file monitoring daemon that detects
                    when files have changed and then performs some action.

           smartd - off SMART Disk Monitoring Daemon. Monitor hard
       drive and predict failure.

              smb - off Samba Windows file sharing server.

            snmpd - off Respond to SNMP request packets. Probably
       only on if another machine is monitoring the
       status of your machine.

        snmptrapd - off Receive and log SNMP trap messages. SNMP is
       for monitoring system status.

     spamassassin - off Mail filter to identify spam using text
       analysis. Only for mail servers(?)

            squid - off Proxy caching server for web and ftp.

             sshd - off SSH daemon. On if you want to ssh into your
       machine.

           syslog - on Handles logging of system events. It is good
                    to leave this turned on. Logs autorotate and will
                    not fill your hard drive.

              tux - off Apparently a web server.

        vncserver - off Remote desktop sharing.

          winbind - off Related to Samba.

              xfs - on X Windows font server. Use by X windows to
       support a graphical desktop (including KDE and Gnome)

           xinetd - on Super daemon (aka super server), launches network related daemons
       on demand.

           ypbind - off Disabled unless you are using and NIS server, usually
       for password authentication

        yppasswdd - off yppasswdd is the RPC server that lets users
       change their passwords when you are using NIS
       (a.k.a. YP).

           ypserv - off ypserv is an implementation of the standard
       NIS/YP networking protocol.

           ypxfrd - off ypxfrd should be started in addition to ypserv to
       accelerate transferring yp maps.

              yum - off Yellow dog Updater, Modified. Updates
              software packages (rpm and/or apt
              packages). Some people run it nightly, some run
              it manually.

ilk kurulum için açmanız gereken ve yeterli olan servisler ise ;

# chkconfig --list |grep 3:on

acpid           3:on  
apmd            3:on   
cpuspeed        3:on   
crond           3:on   
haldaemon       3:on   
ipmi            3:on   
irqbalance      3:on   
messagebus      3:on  
network         3:on   
sendmail        3:on   
sshd            3:on   
syslog          3:on   
xinetd          3:on