Setting Up NFS Server And Client On CentOS 7

NFS, stands for Network File System, is a server-client protocol used for sharing files between linux/unix to unix/linux systems. NFS enables you to mount a remote share locally. You can then directly access any of the files on that remote share.

Scenario

In this how-to, I will be using two systems which are running with CentOS 7. The same steps are applicable for RHEL and Scientific Linux 7 distributions.

Here are mt testing nodes details.

NFS Server Hostname: server.unixmen.local
NFS Server IP Address: 192.168.1.101/24
NFS Client Hostname: client.unixmen.local
NFS Client IP Address: 192.168.1.102/24

Server Side Configuration

Install NFS packages in your Server system by using the following command:

yum install nfs-utils nfs-utils-lib

Enable and start NFS services:

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

Now, let us create some shared directories in server.

Create a shared directory named ‘/var/unixmen_share’ in server and let the client users to read and write files in that directory.

mkdir /var/unixmen_share 
chmod 777 /var/unixmen_share/

Export shared directory on NFS Server:

Edit file /etc/exports,

vi /etc/exports

Add the following line:

/var/unixmen_share/     192.168.1.0/24(rw,sync,no_root_squash,no_all_squash)

where,

/var/unixmen_share – shared directory
192.168.1.0/24 – IP address range of clients
rw – Writable permission to shared folder
sync – Synchronize shared directory
no_root_squash – Enable root privilege
no_all_squash - Enable user’s authority

Restart the NFS service:

systemctl restart nfs-server

Client Side Configuration

Install NFS packages in your client system by using the following command:

yum install nfs-utils nfs-utils-lib

Enable and start NFS services:

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

Mount NFS shares On clients

Create a mount point to mount the shared folder ‘var/unixmen_share’ which we’ve created before in the server.

mkdir /var/nfs_share

Mount the share from server to client as shown below

mount -t nfs 192.168.1.101:/var/unixmen_share/ /var/nfs_share/ 

Sample Output:

mount.nfs: Connection timed out

Probably, it will show a connection timed out error which means that the firewall is blocking our NFS server. To access NFS shares from remote clients, we must allow the following nfs ports in the NFS server iptables/firewall.

If you don’t know which ports to allow through firewall, run the following command:

rpcinfo -p

Sample output:

    program vers proto   port  service
    100000    4   tcp    111  portmapper
    100000    3   tcp    111  portmapper
    100000    2   tcp    111  portmapper
    100000    4   udp    111  portmapper
    100000    3   udp    111  portmapper
    100000    2   udp    111  portmapper
    100024    1   udp  60985  status
    100024    1   tcp  54302  status
    100005    1   udp  20048  mountd
    100005    1   tcp  20048  mountd
    100005    2   udp  20048  mountd
    100005    2   tcp  20048  mountd
    100005    3   udp  20048  mountd
    100005    3   tcp  20048  mountd
    100003    3   tcp   2049  nfs
    100003    4   tcp   2049  nfs
    100227    3   tcp   2049  nfs_acl
    100003    3   udp   2049  nfs
    100003    4   udp   2049  nfs
    100227    3   udp   2049  nfs_acl
    100021    1   udp  46666  nlockmgr
    100021    3   udp  46666  nlockmgr
    100021    4   udp  46666  nlockmgr
    100021    1   tcp  42955  nlockmgr
    100021    3   tcp  42955  nlockmgr
    100021    4   tcp  42955  nlockmgr
    100011    1   udp    875  rquotad
    100011    2   udp    875  rquotad
    100011    1   tcp    875  rquotad
    100011    2   tcp    875  rquotad

You should allow the above ports.

To do that, go to the NFS server, and run the following commands:

firewall-cmd --permanent --add-port=111/tcp
firewall-cmd --permanent --add-port=54302/tcp
firewall-cmd --permanent --add-port=20048/tcp
firewall-cmd --permanent --add-port=2049/tcp
firewall-cmd --permanent --add-port=46666/tcp
firewall-cmd --permanent --add-port=42955/tcp
firewall-cmd --permanent --add-port=875/tcp

Restart firewalld service to take effect the changes:

firewall-cmd --reload

Again mount the share in client system with command:

mount -t nfs 192.168.1.101:/var/unixmen_share/ /var/nfs_share/

Now the NFS share will mount without any connection timed out error.

Verifying NFS Shares On Clients

Verify the share from the server is mounted or not using ‘mount’ command.

mount

Sample output:

proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime,seclabel)
devtmpfs on /dev type devtmpfs (rw,nosuid,seclabel,size=309620k,nr_inodes=77405,mode=755)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,seclabel)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,seclabel,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,seclabel,mode=755)
tmpfs on /sys/fs/cgroup type tmpfs (rw,nosuid,nodev,noexec,seclabel,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
configfs on /sys/kernel/config type configfs (rw,relatime)
/dev/mapper/centos-root on / type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=32,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,seclabel)
mqueue on /dev/mqueue type mqueue (rw,relatime,seclabel)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
/dev/sda1 on /boot type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw,relatime)
sunrpc on /proc/fs/nfsd type nfsd (rw,relatime)
192.168.1.101:/var/unixmen_share on /var/nfs_share type nfs4 (rw,relatime,vers=4.0,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.102,local_lock=none,addr=192.168.1.101)

Auto mount NFS Shares

To mount the shares automatically instead of mounting them manually on every reboot, add the following lines shown in bold in the ‘/etc/fstab’ file of your client system.

vi /etc/fstab
#
# /etc/fstab
# Created by anaconda on Tue Aug 19 12:15:24 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root /                       xfs     defaults        1 1
UUID=2ba8d78a-c420-4792-b381-5405d755e544 /boot                   xfs     defaults        1 2
/dev/mapper/centos-swap swap                    swap    defaults        0 0
192.168.1.101:/var/unixmen_share/ /var/nfs_share/ nfs rw,sync,hard,intr 0 0

Reboot the client system and check the share whether it is automatically mounted or not.

mount

Sample output:

proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime,seclabel)
devtmpfs on /dev type devtmpfs (rw,nosuid,seclabel,size=309620k,nr_inodes=77405,mode=755)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,seclabel)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,seclabel,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,seclabel,mode=755)
tmpfs on /sys/fs/cgroup type tmpfs (rw,nosuid,nodev,noexec,seclabel,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
configfs on /sys/kernel/config type configfs (rw,relatime)
/dev/mapper/centos-root on / type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=32,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,seclabel)
mqueue on /dev/mqueue type mqueue (rw,relatime,seclabel)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
/dev/sda1 on /boot type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw,relatime)
sunrpc on /proc/fs/nfsd type nfsd (rw,relatime)
192.168.1.101:/var/unixmen_share on /var/nfs_share type nfs4 (rw,relatime,vers=4.0,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.102,local_lock=none,addr=192.168.1.101)

Thats it. Now NFS server is ready to use.