Introduction to NFS
NFS is the abbreviation of Network File System. Different operating systems and different hosts can share resources (files or directories) with each other through the TCP/IP network.
NFS relies on the RPC (remote Procedure Call) protocol during file transfer or information transfer. The RPC protocol is a mechanism that enables clients to execute programs in other systems. NFS itself does not provide protocols and functions for information transmission.
The relationship between NFS and RPC Simply put, NFS is a file system, and RPC is responsible for the transmission of information
NFS service installation
Server
# 安装nfs-utils和rpcbind
yum -y install nfs-utils rpcbind
# 启动nfs和rpc服务并加入开机启动
systemctl enable rpcbind nfs --now
# 查看端口注册信息
rpcinfo -p localhost
client
# 安装nfs-utils和rpcbind
yum -y install nfs-utils
systemctl enable nfs --now
NFS configuration
Create a shared directory on the server
# 创建共享目录
mkdir -p /data/share
# 给共享文件夹赋权
chmod 777 /data/share/
# 修改配置文件
vim /etc/exports
# 共享目录 授权挂载网段 挂载权限
/data/share 192.168.1.0/24(rw,sync,no_root_squash)
# 设置完挂载目录后需要重新加载下nfs配置文件
systemctl reload nfs
Commonly used NFS mount parameters
| parameter | illustrate |
|---|---|
| ro | read-only access |
| rw | read and write access |
| sync | When data is written to memory, save data to disk at the same time |
| all_squash | No matter which user the NFS client accesses as, it is mapped to the nfsnobody user of the NFS server |
| no_all_squash | No matter what user is used, the permissions are not compressed, and the UID and GID of the shared file are reserved (default) |
| root_squash | When the NFS client accesses as the root user, it is mapped to the nfsnobody user of the NFS server |
| no_root_squash | When the NFS client accesses as root, it is mapped to the root user of the NFS server, that is, permissions must be reserved for the super user. This option will leave serious security risks and is generally not recommended |
| anunuid=“ ” | Specifies the UID of the anonymous user of the nfs server |
| anonid=“ ” | Specifies the GID of the anonymous user of the nfs server |
View NFS shared directory
Test on the server
showmount -e localhost
Test on the client
showmount -e 192.168.1.200
NFS mount and use
Go to the client to mount the shared directory
# 此挂载方式是临时挂载机器一重启挂载就会丢失。
mount 192.168.1.200:/data/share /data/
#服务端IP:共享目录 #挂载到本地那个目录
view mount
#df -Th|grep nfs
Unmount the mount directory
umount /data
Permanently mount the shared directory
The mount directory needs to be written into the /etc/fstab file to achieve permanent mount
vim /etc/fstab
192.168.1.200:/data/share /data nfs defaults 0 0
In this way, even if the server restarts, the directory can be automatically mounted