NFS

ToolsLinux

Network File System (NFS) is a popular distributed filesystem protocol that enables users to mount remote directories on their server. It does not require client to have big disk space to store all files. NFS lets you leverage storage space in a different location and allows you to write onto the same space from multiple servers or clients in an effortless manner. Following commands are used to config CentOS 7.6 server.

At NFS Server End

Install Required Packages

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yum install nfs-utils
mkdir /var/nfsshare
chmod -R 755 /var/nfsshare
chown nfsnobody:nfsnobody /var/nfsshare

Start the Services and Enable Boot Time Running

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systemctl enable rpcbind
systemctl enable nfs-server
systemctl enable nfs-lock
systemctl enable nfs-idmap
systemctl start rpcbind
systemctl start nfs-server
systemctl start nfs-lock
systemctl start nfs-idmap

Config File

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vim /etc/exports

write the following to make a sharing point into the file.

/var/nfsshare 192.168.0.101(rw,sync,no_root_squash,no_all_squash)

and then restart

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systemctl restart nfs-server

Add the NFS service override in CentOS 7 firewall-cmd public zone service

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firewall-cmd --permanent --zone=public --add-service=nfs
firewall-cmd --permanent --zone=public --add-service=mountd
firewall-cmd --permanent --zone=public --add-service=rpc-bind
firewall-cmd --reload

NFS Client End

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yum install nfs-utils
mkdir -p /mnt/nfs/var/nfsshare
mount -t nfs 192.168.0.100:/var/nfsshare /mnt/nfs/var/nfsshare/
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[root@client1 ~]# df -kh
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/centos-root        39G  1.1G   38G   3% /
devtmpfs                      488M     0  488M   0% /dev
tmpfs                         494M     0  494M   0% /dev/shm
tmpfs                         494M  6.7M  487M   2% /run
tmpfs                         494M     0  494M   0% /sys/fs/cgroup
/dev/mapper/centos-home        19G   33M   19G   1% /home
/dev/sda1                     497M  126M  372M  26% /boot
192.168.0.100:/var/nfsshare   39G  980M   38G   3% /mnt/nfs/var/nfsshare
192.168.0.100:/home           19G   33M   19G   1% /mnt/nfs/home

Permanent NFS mounting

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vim /etc/fstab
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[...]
192.168.0.100:/var/nfsshare    /mnt/nfs/var/nfsshare   nfs defaults 0 0

Got a Problem?

Sometimes, you may got message like you’re denied access to the server, to solve this firstly we should check the log.

tail -n100 /var/log/messages

In my case, I was working on a KVM(Kernel-based Virtual Machine) which is use it’s own IP, but the NFS server got its host IP, in the configuration file of the NFS server, I added the KVM IP, so the miss-match of IP address caused a denial of access.

Change /etc/exports

It is not required to restart NFS every time you make a change to /etc/exports. What we need is to issue the appropriate command after editing the /etc/exports file:

exportfs -ra