File Operations of the NFS service

We have explained a lot about NFS service settings. Here we will summarize the main points in this regard. I hope this will help you. Network File System (NFS) allows you to share directories of different hosts (OS) over the Network-you can mount directories of remote hosts through NFS, accessing this directory is like accessing a local directory! Generally, nfs can be used to easily share unix-like systems. However, to share unix-like systems with windows systems, samba must be used! Based on SUN's Remote Procedure Call (Remote Procedure Call), RPC defines a system-independent method for inter-process communication. therefore, the NFS server can also be viewed as an RPC server.

Because NFS is an RPC service program, you must map the port before using it-set it through portmap. for example, when an NFS client initiates an NFS service request, it must first obtain a port ). therefore, it first obtains the port number through portmap. (not only NFS, but portmap needs to be set before all RPC service programs start)

Before starting the RPC service (such as NFS), you need to start the portmap service! (For more information about whether nfs and portmap exist in the current system, see the "NFS installation" section.

Several NFS-related files and commands

1/etc/exports

The access to the NFS volume is approved by exports, which enumerate several hostnames that have the right to access the file system on the NFS server.

2/sbin/exportfs

Maintain NFS Resource Sharing. You can reset the shared directory of/etc/exports, unmount the shared directory of NFS Server, or share it again.

3/usr/sbin/showmount

It is used on the NFS Server, while showmount is mainly used on the Client. showmount can be used to view NFS shared directory resources.

4/var/lib/nfs/xtab

NFS record document: You can view which clients are connected to the NFS host.

The following are not directly responsible for NFS. In fact, they are responsible for all RPC

5/etc/default/portmap

In fact, portmap maps all the RPC service ports. Its content is very simple (detailed later)

6/etc/hosts. deny

Set the host to reject the portmap service

7/etc/hosts. allow

Set the host that allows the portmap service

Install NFS

By default, the NFS server is not installed on Debian/Ubuntu. First, install the NFS service program:

$ Sudo apt-get install nfs-kernel-server

(When nfs-kernel-server is installed, apt will automatically install nfs-common and portmap)

In this way, the host is equivalent to the NFS Server.

Similarly, if the target system is an NFS client, you must install the NFS client program. If it is a Debian/Ubuntu system, you must install nfs-common.

$ Sudo apt-get install nfs-commmon

Both nfs-common and nfs-kernel-server depend on portmap!

Configure NFS

NFS is an RPC server program, and portmap is used to mount the RPC port ing. You must configure portmap first.

Configure portmap

Method 1: edit/etc/default/portmap and remove-I 127.0.0.1.

Method 2: $ sudo dpkg-reconfigure portmap. Select N for shocould portmap be bound to the loopback address.

Configure/etc/hosts. deny

(Prohibit any host (host) from connecting to your NFS server), add:

### NFS DAEMONS

Portmap: ALL

Lockd: ALL

Mountd: ALL

Rquotad: ALL

Statd: ALL

Configure/etc/hosts. allow

Allow the hosts you want to establish connections with your NFS server. the following steps allow any host whose IP address starts with 192.168.2 (connected to the NFS server), or specify a specific IP address. see hosts_access (5) and hosts_options (5) on the man page ). join:

### NFS DAEMONS

Portmap: 192.168.2.

Lockd: 192.168.2.

Rquotad: 192.168.2.

Mountd: 192.168.2.

Statd: 192.168.2.

/Etc/hosts. deny and/etc/hosts. allow sets the access to portmap. using these two configuration files is a bit similar to "mask. now/etc/hosts. deny prohibits all users from accessing portmap. then in/etc/hosts. some users are allowed to access portmap in allow.

Run $ sudo/etc/init. d/portmap restart to restart portmap daemon.

Configure/etc/exports

The NFS mount directory and permissions are defined by the/etc/exports file.

For example, to share the IP address of 192.168.2. * In the/home/zp/share directory of my home directory, add the following statement at the end of the file:

/Home/zp/share 192.168.2. * (rw, sync, no_root_squash)

Or:/home/zp/share 192.168.2.0/24 (rw, sync, no_root_squash)

192.168.2. * The NFS client in the network segment can share the contents of the NFS server/home/zp/share directory. the user has the read and write permissions, and the user's identity after entering the/home/zp/share directory is root

It is best to add sync. Otherwise, a warning will be given when $ sudo exportfs-r is used. sync is the default option of NFS.

Run $ showmount-e to view the NFS server's export list.

If/etc/exports is changed, run $ sudo exportfs-r update.

Run $ sudo/etc/init. d/nfs-kernel-server restart to restart the nfs service.

/Etc/exports is actually the core configuration file of the nfs server. laruence's Linux private dish lists the writing of some exports files.

Test NFS

Try mounting the local disk (assuming the IP address of the local host is 192.128.2.1, Mount/home/zp/share to/mnt)

$ Sudo mount 192.168.2.1:/home/zp/share/mnt

Run $ df to check the result

$ Sudo umount/mnt

Pay attention to the read and write permissions of the Copied object!

In addition, some parameters can be used:

Add parameters: mount-o nolock, rsize = 1024, wsize = 1024, timeo = 15 192.168.2.130:/tmp // tmp/