Found a swap file by the name "/etc/.dhcpd.conf.swp"
owned by: root dated: Mon Nov 18 10:04:46 2013
file name: /etc/dhcpd.conf
user name: root host name: jbf.com
process ID: 24031
While opening file "/etc/dhcpd.conf"
dated: Fri Nov 22 16:22:27 2013
NEWER than swap file!
(1) Another program may be editing the same file.
If this is the case, be careful not to end up with two
different instances of the same file when making changes.
Quit, or continue with caution.
(2) An edit session for this file crashed.
If this is the case, use ":recover" or "vim -r /etc/dhcpd.conf"
to recover the changes (see ":help recovery").
If you did this already, delete the swap file "/etc/.dhcpd.conf.swp"
to avoid this message.
Swap file "/etc/.dhcpd.conf.swp" already exists!
解决办法：ls -la 然后删除/etc/.dhcpd.conf.swp缓存文件，即可恢复正常。