出现此类错误原因大致为：
- 权限问题
- 防火墙机制问题
- 共享配置文件问题
搭建好nfs服务后，在client端进行挂载时，提示：
[root@web1 media]# mount -t nfs 192.168.0.124:/server/tools/repo /media/centos/ mount.nfs: access denied by server while mounting 192.168.0.124:/server/tools/repo
查看了一下client端是否被占用了：
[root@web1 media]# mount -t nfs 192.168.0.124:/server/tools/repo /media/centos/ mount.nfs: access denied by server while mounting 192.168.0.124:/server/tools/repo [root@web1 media]# mount /dev/sda3 on / type ext4 (rw) proc on /proc type proc (rw) sysfs on /sys type sysfs (rw) devpts on /dev/pts type devpts (rw,gid=