# showmount -e
mount clntudp_create: RPC: Port mapper failure - RPC: Timed out
可能的原因
a) Portmap没有正常启动启动

b) 当NFS Server 上面的/etc/hosts文件中的域名与本机ＩＰ不对称时，会出现无法导出共享目录的现象。即exportfs 命令导出共享时间极长，导致无法导出，或者showmount –e命令显示本机共离时显示” mount clntudp_create: RPC: Port mapper failure - RPC: Timed out”错误。
查看本机/etc/hosts
# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6
220.250.64.23           server.XXX.cn server
果然如此把最后一行改为
192.168.0.X               server.XXX.cn server
 
问题解决
# showmount -e
Export list for server.XXX.cn:
/install/rhel *