When Linux server boots up a large amount of services keeps running in its background . Some services are essential to the operation of your server, while other services are considered non-essential and will cause no problems to your server by disabling them. Some services takes a lot of time and may affect the working of some of your applications. We can disable these services during boot up.
To list all the services that are started at boot up type command
chkconfig --list |grep on
We can see a quite a lot of services are enabled and disabled on the server for different run levels.
Some of the services like ( autofs, avahi-daemon, avahi-dnsconfd, bluetooth, conman, cups, dhcdbd, firstboot, gpm, haldaemon, isdn, iptables, ip6tables, irda, irqbalance, kdump, kudzu, mcstrans, microcode_ctl, multipathd, netconsole, netfs, netplugd, nfs, nfslock, nscd, pcscd, rdisc, rhnsd, restorecond, rpcgssd, rpcidmapd, rpcsvcgssd, sendmail, smartd, winbind, wpa_supplicant, xfs, ypbind, yum-updatesd) are not that necessary for the server working. We can disable these services .
To permanently disable e.g. the runlevel service bluetooth, run:
chkconfig bluetooth off
To immediately disable the runlevel service bluetooth, run: