第一步、删除不必要的自带软件包

yum remove Deployment_Guide-en-US finger cups-libs cups ypbind

yum remove bluez-libs desktop-file-utils ppp rp-pppoe wireless-tools irda-utils

yum remove sendmail* samba* talk-server finger-server bind* xinetd

yum remove nfs-utils nfs-utils-lib rdate fetchmail eject ksh mkbootdisk mtools

yum remove syslinux tcsh startup-notification talk apmd rmt dump setserial portmap yp-tools

yum groupremove "Mail Server" "Games and Entertainment" "X Window System" "X Software Development"

yum groupremove "Development Libraries" "Dialup Networking Support"

yum groupremove "Games and Entertainment" "Sound and Video" "Graphics" "Editors"

yum groupremove "Text-based Internet" "GNOME Desktop Environment" "GNOME Software Development"

第二步、升级centos系统

yum update #更新系统

yum clean all #清理全部缓存文件

第三步、禁用seLinux

sestatus #先执行看seLinux状态，如果不是disabled，就需要执行下面步骤，否则不要执行

vi /etc/selinux/config

SELINUX=disabled #禁用SeLinux

SELINUX=enforcing #使用SeLinux

第四步、禁止IPV6（执行后需要reboot重启）

vi /etc/modprobe.conf #打开文件，把下面两行加到最后

alias net-pf-10 off

alias ipv6 off

第五步、初始化防火墙

touch /etc/sysconfig/iptables

iptables -F

iptables -X

iptables -Z

service iptables save

service iptables restart

第六步、禁止无用服务

#! /bin/bash

service acpid off

service atd stop

service auditd stop

service avahi-daemon stop

service avahi-dnsconfd stop

service bluetooth stop

service conman stop

service cpuspeed stop

service cups stop

service dnsmasq stop

service dund stop

service firstboot stop

service hidd stop

service httpd stop

service ibmasm stop

service ip6tables stop

service irda stop

service kdump stop

service lm_sensors stop

service mcstrans stop

service messagebus stop

service microcode_ctl stop

service netconsole stop

service netfs stop

service netplugd stop

service nfs stop

service nfslock stop

service nscd stop

service ntpd stop

service oddjobd stop

service pand stop

service pcscd stop

service portmap stop

service psacct stop

service rdisc stop

service restorecond stop

service rpcgssd stop

service rpcidmapd stop

service rpcsvcgssd stop

service saslauthd stop

service sendmail stop

service setroubleshoot stop

service smb stop

service vncserver stop

service winbind stop

service wpa_supplicant stop

service xfs stop

service ypbind stop

service yum-updatesd stop

chkconfig acpid off

chkconfig atd off

chkconfig auditd off

chkconfig avahi-daemon off

chkconfig avahi-dnsconfd off

chkconfig bluetooth off

chkconfig conman off

chkconfig cpuspeed off

chkconfig cups off

chkconfig dnsmasq off

chkconfig dund off

chkconfig firstboot off

chkconfig hidd off

chkconfig httpd off

chkconfig ibmasm off

chkconfig ip6tables off

chkconfig irda off

chkconfig kdump off

chkconfig lm_sensors off

chkconfig mcstrans off

chkconfig messagebus off

chkconfig microcode_ctl off

chkconfig netconsole off

chkconfig netfs off

chkconfig netplugd off

chkconfig nfs off

chkconfig nfslock off

chkconfig nscd off

chkconfig ntpd off

chkconfig oddjobd off

chkconfig pand off

chkconfig pcscd off

chkconfig portmap off

chkconfig psacct off

chkconfig rdisc off

chkconfig restorecond off

chkconfig rpcgssd off

chkconfig rpcidmapd off

chkconfig rpcsvcgssd off

chkconfig saslauthd off

chkconfig sendmail off

chkconfig setroubleshoot off

chkconfig smb off

chkconfig vncserver off

chkconfig winbind off

chkconfig wpa_supplicant off

chkconfig xfs off

chkconfig ypbind off

chkconfig yum-updatesd off

这样通过上述6步骤，就可以完成对centos精简和优化。