File has not been synchronized when NFS is mounted

NFS After installation , There are the following precautions for mounting ：

1. Development board and Linux Should be able to interact with each other ping through .

2. stay mount And umount（ Unmount ） In operation , The current path of the user cannot be the target path of the operation .

3. Execute mount command , Such as mount -t nfs -o nolock,vers=3 192.168.0.103:/home/book/nfs_rootfs /mnt when , In the command IP192.168.0.103 And the colon after it : There must be no space between them .