[root@MyVPS1218 ~]# hostname -i
hostname: Unknown host
解决办法：先查本机的“hostname”为 MyVPS1218
[root@MyVPS1218 ~]# hostname
MyVPS1218
编辑 /etc/hosts ，在 127.0.0.1 这行结尾加上这台机器的“hostname”MyVPS1218 ，改为
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 MyVPS localhost.localdomain localhost MyVPS1218
::1 localhost6.localdomain6 localhost6
再试，成功！
[root@MyVPS1218 ~]# hostname -i
127.0.0.1 | 