Linux NFS Introduction

The NFS (Network File system), which is one of the file systems supported by FreeBSD, allows computers in the network to share resources across TCP/IP networks. In an NFS application, a local NFS client application can transparently read and write to files located on the remote NFS server, just as you would access a local file.

Use Scenario: Personal recommended NFS file system is best built in the intranet, suitable for small and medium-sized network services file sharing

1. Installation

[[email protected] ~]# yum -y install nfs-utils rpcbind[[email protected] ~]# rpm -ql nfs-utils/usr/lib/systemd/system/nfs.service/usr/lib/systemd/system/nfs-lock.service/usr/lib/systemd/system/nfs-mountd.service/usr/lib/systemd/system/rpc-statd.service....

2. Create a directory to export

[[email protected] /]# mkdir /nfsshared/node1 -pv

3. Export Configuration file Description

/etc/exports或/etc/exports.d/*    /PATH/TO/SOME_DIR   clients1(export_options, ...)  clients2(export_options, ...)        clients：            single host：ipv4, ipv6, FQDN；            network：address/netmask， 支持长短格式的掩码；            wildcards：主机名通配，例如：*.zander.com;             netgroups：NIS域内的主机组；@group_name；            anonymous：使用*通配所有主机；        General Options:            ro：只读            rw：读写；            sync：同步；            async：异步；            secure：客户端端口小于1024，否则就要使用insecure选项；        User ID Mapping：             root_squash：压缩root用户，一般指将其映射为nfsnobody；             no_root_squash：不压缩root用户；             all_squash：压缩所有用户；             anonuid and anongid：将压缩的用户映射为此处指定的用户；

3.1. Configuration files

[[email protected] /]# vim /etc/exports/nfsshared/node1 172.16.86.210/24(rw)#mount端口应该固定防止占用其他端口[[email protected] node1]# vim /etc/sysconfig/nfs MOUNTD_PORT=892

4. Start

[[email protected] /]# systemctl start nfs#nfs内部实现机制太复杂了nfs-idmapd.service                 loaded active running NFSv4 ID-name mapping service   id名字映射nfs-mountd.service                 loaded active running NFS Mount Daemon       认证挂载nfs-server.service                 loaded active exited  NFS server and services  主服务rpc-statd.service                  loaded active running NFS status monitor for NFSv2/3 locking. 状态监控rpcbind.service                    loaded active running RPC bind service         nfs注册到rpc服务

5, the Client

[[email protected] test]# yum install nfs-utils[[email protected] test]# showmount -e 172.16.86.210Export list for 172.16.86.210:/nfsshared/node1 172.16.86.210/24#挂载[[email protected] test]# mount.nfs 172.16.86.210:/nfsshared/node1 /mnt/t4[[email protected] test]# mount|grep nfs172.16.86.210:/nfsshared/node1 on /mnt/t4 type nfs4 (rw,relatime,vers=4.1,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=172.16.86.209,local_lock=none,addr=172.16.86.210)客户端挂载优化参数timeo增加，rsize wsize增大

6. Write

 #写入时候文件都是看当前用户的id，id解析成用户名压缩理解客户端如果是root  ID=0服务器如果不压缩，文件写入id=0   服务器解释id=0 为root，客户端也是root服务器如果压缩，文件写入id是服务器nfsnobody对应id  假如是100   客户端反接100得到用户名普通用户，客户端写入时候是zander id=10000  ,显示zander，服务器端显示id=10000的用户#服务器[[email protected] node1]# chmod o+w f1/[[email protected] node1]# lsf1#客户端在f1下面写入[[email protected] f1]# touch a.txt[[email protected] f1]# lltotal 0-rw-r--r-- 1 nfsnobody nfsnobody 0 May 20 22:09 a.txt

6.1 The best way to write

 指定用户客户端无论什么身份运行，服务器都是按照指定的用户存储，客户端反解服务器指定用id来显示，前提是服务器指定的用户要有对目录操作权限服务器[[email protected] f1]# useradd marvin[[email protected] f1]# id marvinuid=1003(marvin) gid=1003(marvin) 组=1003(marvin)[[email protected] f1]# vim  /etc/exports/nfsshared/node1 172.16.86.210/24(rw,anonuid=1003,anongid=1003)#reload[[email protected] f1]# exportfs -ravexporting 172.16.86.210/24:/nfsshared/node1#客户端[[email protected] f1]# touch c.txt[[email protected] f1]# lsc.txt[[email protected] f1]# lltotal 0-rw-r--r-- 1      1003      1003 0 May 20 22:27 c.txt

Linux NFS Introduction