1.什么是NFS
  
2.Ubuntu安装软件包的方式与下载位置
   Linux和Windows完全不一样,Windows习惯把一个软件安装在一个文件夹里面,而Linux是将一个软件分散安装的不同的文件夹.
   dpkg -L 软件包名--->查看文件软件包里的文件,如果包安装成功的话,会列出所有文件的位置.
   apt-get 所下载的用于安装的软件包,在Ubuntu中的位置为/var/cache/apt/archives中.
   如果执行过apt-get clean,那么原始下载的包就就会被清理.
  

3.安装步骤
  (1).安装nfs-kernel-server软件包
      命令:sudo apt-get install nfs-kernel-server

   (2).创建NFS目录,并设置其权限
       命令:sudo mkdir /nfs
             sudo chmod 777 /nfs

   (3).配置NFS资源
       命令:sudo vim /etc/exports

       打开后文件内容如下:
       -------------------
       # /etc/exports: the access control list for filesystems which may be exported
       #               to NFS clients.  See exports(5).
       #
       # Example for NFSv2 and NFSv3:
       # /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
       #
       # Example for NFSv4:
       # /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
       # /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)
       #

       修改为如下内容保存:
       -------------------
       # /etc/exports: the access control list for filesystems which may be exported
       #               to NFS clients.  See exports(5).
       #
       # Example for NFSv2 and NFSv3:
       # /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
       #
       # Example for NFSv4:
       # /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
       # /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)
       #
       /nfs *(rw,sync,no_root_squash,no_subtree_check)

   (4).手动启动/停止/重启服务
       命令:sudo /etc/init.d/nfs-kernel-server start

       Linux 终端显示内容为:
       -----------------------
       * Exporting directories for NFS kernel daemon...                         [ OK ]
       * Starting NFS kernel daemon                                             [ OK ]

       命令:sudo /etc/init.d/nfs-kernel-server stop

       Linux 终端显示内容为:
       -----------------------
       * Stopping NFS kernel daemon                                             [ OK ]
       * Unexporting directories for NFS kernel daemon...                       [ OK ]

       命令:sudo /etc/init.d/nfs-kernel-server restart

       Linux 终端显示内容为:
       -----------------------
       * Stopping NFS kernel daemon                                             [ OK ]
       * Unexporting directories for NFS kernel daemon...                       [ OK ]
       * Exporting directories for NFS kernel daemon...                         [ OK ]
       * Starting NFS kernel daemon                                             [ OK ]

   (5).查看NFS服务器的共享资源
       挂载共享资源
       命令: sudo mount -t nfs 127.0.0.1:/nfs /mnt/

       卸载共享资源
       命令:sudo umount /mnt/

4.卸载NFS软件包
   命令:apt-get remove nfs-kernel-server