# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
baseurl=http://mirrors.shlug.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=1
#released updates
[updates]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.shlug.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=1
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
baseurl=http://mirrors.shlug.org/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=0
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.shlug.org/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=0
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.shlug.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
protect=1
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib
baseurl=http://mirrors.shlug.org/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
protect=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
保存文件。
（4）更新系统，我们使用yum,
运行：
# yum upgrade
建议更新所有列出的程序，包括内核，rhel 5.X的稳定性还要继续努力呢。
（5）定时校正服务器时间
# yum install –y ntp
# crontab -e
0 23 * * * /usr/sbin/ntpdate 210.72.145.44
以上命令设置好后存盘。
# /sbin/service crond reload
重载计划任务配置
您的机器将在每天的23:00根据中国国家授时中心的NTP服务器时间自动校准时间。
（6）FTP服务器的配置
vi /etc/vsftpd/vsftpd.conf
把anonymous_enable=YES
修改为anonymous_enable=No不允许匿名登录。
添加两句
chroot_local_user=yes
listen_port=2121
将用户锁定在主目录，并将FTP监听端口修改为2121
把ftpd_banner=*前的注释去掉。后面改成你的欢迎信息(这样设置可以避免显示ftp服务器的版本信息)
