How to Setup Standard Linux FS & Configure NFSv4 Server
To Set up Standard Linux File Systems and Configure NFSv4 Server
In this article we are going to discuss how to set up Standard Linux File Systems and configure NFSv4 Server. NFS Server will provides a service to share files over a network to Linux Clients.
Before going to configure NFS server, just make sure the NFS server is up and running.
Do the following process once the NFS server is set,
&rarr To configure NFS server to share a local directory over a network.
&rarr Automatically Mount those network shares in clients, either via the /etc/fstab file or autofs.
Server and Client Configuration
Before going to configure NFS server note the IP for Server and Client that we are going to use here,
Server IP : 192.168.5.88
Clinet IP : 192.168.5.89
To install package for NFS
To set up NFS server we need to install the NFS server package. The package may differ depending upon your linux distribution. For RedHat based distributions, run the below command to install the NFS packages.
[root@linuxhelp ~]# yum install nfs* -y
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Resolving Dependencies
There are unfinished transactions remaining. You might consider running yum-complete-transaction, or " yum-complete-transaction --cleanup-only" and " yum history redo last" , first to finish them. If those don' t work you' ll have to try removing/installing packages by hand (maybe package-cleanup can help).
--> Running transaction check
---> Package nfs-utils.x86_64 1:1.3.0-0.el7 will be installed
---> Package nfs4-acl-tools.x86_64 0:0.3.3-13.el7 will be installed
---> Package nfsometer.noarch 0:1.7-0.el7 will be installed
---> Package nfstest.noarch 0:1.0.2-2.el7 will be installed
.
.
. 2/4
Verifying : nfs4-acl-tools-0.3.3-13.el7.x86_64 3/4
Verifying : nfsometer-1.7-0.el7.noarch 4/4
Installed:
nfs-utils.x86_64 1:1.3.0-0.el7 nfs4-acl-tools.x86_64 0:0.3.3-13.el7 nfsometer.noarch 0:1.7-0.el7 nfstest.noarch 0:1.0.2-2.el7
Complete!
Now the installation is successfully completed.
To Export NFS Network Shares
The /etc/exports file is used for exporting the NFS share to remote hosts. Mention the absolute path for the exporting NFS share to our clients with client IP address or hostname with permissions. We are going to share the /nfsshare directory, so its ownership permission should be set to nfsnobody to make our shares writable for our clients.
[root@linuxhelp ~]# ls -l /
total 32
lrwxrwxrwx. 1 root root 7 Apr 26 2016 bin -> usr/bin
dr-xr-xr-x. 4 root root 4096 Apr 26 14:33 boot
drwxr-xr-x. 19 root root 3260 Apr 26 14:33 dev
drwxr-xr-x. 128 root root 8192 Apr 26 16:46 etc
drwxr-xr-x. 3 root root 18 Apr 26 2016 home
lrwxrwxrwx. 1 root root 7 Apr 26 2016 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 Apr 26 2016 lib64 -> usr/lib64
drwxr-xr-x. 2 root root 6 Jun 10 2014 media
drwxr-xr-x. 2 root root 6 Jun 10 2014 mnt
drwxr-xr-x. 2 root root 6 Apr 26 16:48 nfsshare
drwxr-xr-x. 3 root root 15 Apr 26 2016 opt
dr-xr-xr-x. 290 root root 0 Apr 26 2016 proc
dr-xr-x---. 16 root root 4096 Apr 26 16:12 root
drwxr-xr-x. 37 root root 1180 Apr 26 16:46 run
lrwxrwxrwx. 1 root root 8 Apr 26 2016 sbin -> usr/sbin
drwxr-xr-x. 2 root root 6 Jun 10 2014 srv
dr-xr-xr-x. 13 root root 0 Apr 26 2016 sys
drwxrwxrwt. 18 root root 4096 Apr 26 16:47 tmp
drwxr-xr-x. 13 root root 4096 Apr 26 2016 usr
drwxr-xr-x. 22 root root 4096 Apr 26 2016 var
[root@linuxhelp ~]# chown nfsnobody: /nfsshare/
[root@linuxhelp ~]# ls -l /
total 32
lrwxrwxrwx. 1 root root 7 Apr 26 2016 bin -> usr/bin
dr-xr-xr-x. 4 root root 4096 Apr 26 14:33 boot
drwxr-xr-x. 19 root root 3260 Apr 26 14:33 dev
drwxr-xr-x. 128 root root 8192 Apr 26 16:46 etc
drwxr-xr-x. 3 root root 18 Apr 26 2016 home
lrwxrwxrwx. 1 root root 7 Apr 26 2016 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 Apr 26 2016 lib64 -> usr/lib64
drwxr-xr-x. 2 root root 6 Jun 10 2014 media
drwxr-xr-x. 2 root root 6 Jun 10 2014 mnt
drwxr-xr-x. 2 nfsnobody nfsnobody 6 Apr 26 16:48 nfsshare
drwxr-xr-x. 3 root root 15 Apr 26 2016 opt
dr-xr-xr-x. 290 root root 0 Apr 26 2016 proc
dr-xr-x---. 16 root root 4096 Apr 26 16:12 root
drwxr-xr-x. 37 root root 1180 Apr 26 16:46 run
lrwxrwxrwx. 1 root root 8 Apr 26 2016 sbin -> usr/sbin
drwxr-xr-x. 2 root root 6 Jun 10 2014 srv
dr-xr-xr-x. 13 root root 0 Apr 26 2016 sys
drwxrwxrwt. 18 root root 4096 Apr 26 16:58 tmp
drwxr-xr-x. 13 root root 4096 Apr 26 2016 usr
drwxr-xr-x. 22 root root 4096 Apr 26 2016 var
[root@linuxhelp ~]# vim /etc/exports
/nfsshare 192.168.5.89(rw,sync,no_root_squash,no_subtree_check)
After exporting the share we need to reload and update the exports share to our kernel. To do that run the below commands. To view the exports share use showmount or exportfs command.
[root@linuxhelp ~]# exportfs -r
[root@linuxhelp ~]# exportfs -a
[root@linuxhelp ~]# exportfs -s
/nfsshare 192.168.5.89(rw,wdelay,root_squash,no_subtree_check,sec=sys,rw,secure,root_squash,no_all_squash)
A list of most-frequent options used while exporting the NFS share:
1. ro : read-only, Remote clients can mount the exported file with read permissions only.
2. rw : read-write, it allows remote hosts to make write changes in the exported file.
3. root_squash : prevents remote root users from privileges in the server and allots them the user ID. If you like to " squash" all then use the option all_squash.
4. wdelay : write delay, NFS server delays committing changes to disk if it guess another related write request is imminent.
5. subtree_check : option verifies that a requested file is located in that exported subdirectoryif not disabling this option with no_subtree_check will fast up transfers. 8. fsid=0 | root denotes that the specified file is the root of multiple exported directories.
6. anonuid / anongid : is explicitly sets the UID and GID.
7. sync : represents the server replies to requests after changes have been committed to the hard disk.
To Open Firewall for NFS shares
Now its time to open our firewall for NFS server to allow our clients to view and mount our exports share. By opening the firewall for rpc-bind service, our clients will be able to view the available share by showmount command and mountd is a daemon for remotely mount our share to clients.
[root@linuxhelp ~]# firewall-cmd --permanent --add-service=nfs success [root@linuxhelp ~]# firewall-cmd --permanent --add-service=rpc-bind success [root@linuxhelp ~]# firewall-cmd --permanent --add-service=mountd success [root@linuxhelp ~]# firewall-cmd --reload success
To restart the NFS service
After exporting and opening the firewall, We need to start and enable the nfs services by executing the below command.
[root@linuxhelp ~]# systemctl start nfs-server
[root@linuxhelp ~]# systemctl enable nfs-server
ln -s ' /usr/lib/systemd/system/nfs-server.service' ' /etc/systemd/system/nfs.target.wants/nfs-server.service'
[root@linuxhelp ~]# systemctl status nfs-server
nfs-server.service - NFS Server
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service enabled)
Active: active (exited) since Tue 2016-04-26 17:06:58 IST 23s ago
Main PID: 42483 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/nfs-server.service
Apr 26 17:06:58 linuxhelp systemd[1]: Starting NFS Server...
Apr 26 17:06:58 linuxhelp systemd[1]: Started NFS Server.
Mounting the NFS share to Clients
Now it’ s time to mount the NFS share in our client machine. To view the available shares use showmount command. To mount the share permanently create an entry in /etc/fstab file and run mount -a to mount all entries in fstab, as follows.
[root@linuxhelp ~]# showmount -e 192.168.5.88
Export list for 192.168.5.88:
/nfsshare 192.168.5.89
[root@linuxhelp ~]# vim /etc/fstab
192.168.5.88:/nfsshare /mnt nfs defaults 0 0
[root@linuxhelp ~]# mount -a
[root@linuxhelp ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 18G 3.3G 15G 19% /
devtmpfs 486M 0 486M 0% /dev
tmpfs 494M 140K 494M 1% /dev/shm
tmpfs 494M 7.1M 487M 2% /run
tmpfs 494M 0 494M 0% /sys/fs/cgroup
/dev/sda1 497M 116M 382M 24% /boot
/dev/sr0 3.9G 3.9G 0 100% /run/media/root/CentOS 7 x86_64
192.168.5.88:/nfsshare 18G 3.5G 15G 20% /mnt
After mounting the share locally move to that mount path and try to create some file to check write permissions is applied or not.
[root@linuxhelp ~]# cd /mnt
[root@linuxhelp mnt]# ls
[root@linuxhelp mnt]# touch file1
[root@linuxhelp mnt]# ls
file1
To Automount the share using Autofs
Autofs is used for automatically mounting and unmounting the shares. Autofs automounts the share when the share is not accessible or available at system boot time. To configure autofs service install the autofs package shown below.
[root@linuxhelp ~]# yum install autofs -y
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: centos.excellmedia.net
* extras: centos.excellmedia.net
* updates: centos.excellmedia.net
Resolving Dependencies
--> Running transaction check
---> Package autofs.x86_64 1:5.0.7-54.el7 will be installed
.
.
Running transaction
Installing : 1:autofs-5.0.7-54.el7.x86_64 1/1
Verifying : 1:autofs-5.0.7-54.el7.x86_64 1/1
Installed:
autofs.x86_64 1:5.0.7-54.el7
To edit auto.master and auto.misc files
After installing autofs package we need to edit the two files auto.master and auto.misc located under the /etc directory as follows. In auto.misc file, mention any name for your share.
[root@linuxhelp ~]# vim /etc/auto.master
/mnt /etc/auto.misc --timeout=60
[root@linuxhelp ~]# vim /etc/auto.misc
Share --rw,sync 192.168.5.88:/nfsshare
To start autofs service
After creating entry in auto.master and auto.misc files just start and enable the autofs service by running the below command.
[root@linuxhelp ~]# systemctl start autofs [root@linuxhelp ~]# systemctl enable autofs ln -s ' /usr/lib/systemd/system/autofs.service' ' /etc/systemd/system/multi-user.target.wants/autofs.service' [root@linuxhelp ~]# systemctl status autofs autofs.service - Automounts filesystems on demand Loaded: loaded (/usr/lib/systemd/system/autofs.service enabled) Active: active (running) since Tue 2016-04-26 17:30:22 IST 20s ago Main PID: 41682 (automount) CGroup: /system.slice/autofs.service ??41682 /usr/sbin/automount --pid-file /run/autofs.pid Apr 26 17:30:22 linuxhelp systemd[1]: Starting Automounts filesystems on demand... Apr 26 17:30:22 linuxhelp systemd[1]: Started Automounts filesystems on demand.
After starting the autofs service, run the following command to view the mount points for your nfs share.
[root@linuxhelp ~]# mount | grep share 192.168.5.88:/nfsshare on /mnt 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=192.168.5.89,local_lock=none,addr=192.168.5.88) [root@linuxhelp ~]# ls -l /mnt total 0 drwxr-xr-x. 2 nfsnobody nfsnobody 18 Apr 26 17:21 share [root@linuxhelp ~]# ls -l /mnt/share total 0 -rw-r--r--. 1 nfsnobody nfsnobody 0 Apr 26 17:21 file1
As you can see a new directory will be created in the name of our share name (share) under our mount point /mnt
Server support for TCP appears in 2.4.19 and later 2.4 kernels, and in 2.6 and later kernels. Not all 2.4-based