[root@teddylu dhcp]# /etc/init.d/dhcpd start
Starting dhcpd: [FAILED]
[root@teddylu dhcp]# tail -15 /var/log/messages
Jul 17 08:06:24 teddylu dhcpd: Copyright 2004-2010 Internet Systems Consortium.
Jul 17 08:06:24 teddylu dhcpd: All rights reserved.
Jul 17 08:06:24 teddylu dhcpd: For info, please visit https://www.isc.org/software/dhcp/
Jul 17 08:06:24 teddylu dhcpd: Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file
Jul 17 08:06:24 teddylu dhcpd: Can't chown new lease file: Operation not permitted
Jul 17 08:06:24 teddylu dhcpd:
Jul 17 08:06:24 teddylu dhcpd: This version of ISC DHCP is based on the release available
Jul 17 08:06:24 teddylu dhcpd: on ftp.isc.org. Features have been added and other changes
Jul 17 08:06:24 teddylu dhcpd: have been made to the base software release in order to make
Jul 17 08:06:24 teddylu dhcpd: it work better with this distribution.
Jul 17 08:06:24 teddylu dhcpd:
Jul 17 08:06:24 teddylu dhcpd: Please report for this software via the CentOS Bugs Database:
Jul 17 08:06:24 teddylu dhcpd: http://bugs.centos.org/
Jul 17 08:06:24 teddylu dhcpd:
Jul 17 08:06:24 teddylu dhcpd: exiting.
其中这一行引起注意
dhcpd: Can't chown new lease file: Operation not permitted
于是检查 /etc/rc.d/init.d/dhcpd 文件，发现其中有如下两行定义了启动dhcp的user和group
user=dhcpd
group=dhcpd
想到可能是用户权限问题，于是把这两个参数修改为：
user=root
group=root
然后再使用 " service dhcpd start" 启动DHCP，问题解决。