|Home||Switchboard||Unix Administration||Red Hat||TCP/IP Networks||Neoliberalism||Toxic Managers|
May the source be with you, but remember the KISS principle ;-)
Skepticism and critical thinking is not panacea, but can help to understand the world better
|Linux Networking||Network File System (NFS)||NFS version 3 Design and Operation|
|Nmap||NetworkManager||Bonding Ethernet Interfaces in RHEL 7|
|Ethernet Protocol||Linux ifconfig||How to change IP address in RHEL||ethtool||Autonegotiation||Traceroute||ntop|
|NTP||RHEL NTP configuration||Troubleshooting NTP on Red Hat Linux||netstat||Disabling RHEL 6 Network Manager|
|Linux Routing||Linux route command||Horror Stories||Unix History||Humor||Etc|
To configure NFS Server, we have to install nfs-utils package. Usually, this package is automatically installed during installation of RHEL or CentOS 7. However, you can install it anytime using yum command.
There are three ways to configure an NFS server under RHEL:
This page discusses the classic Unix way: manually editing /etc/exports and using the /usr/sbin/exportfs command to export NFS file systems.
On RHEL 7, NFS 4 is the default version of NFS. If when making an NFS mount the NFS server offers a previous version of NFS, the client falls automatically back to that version. From a client, you can also force a specific NFS version to be used for the mount, by using the nfsvers= mount option. This can prove useful if you are connecting to a server or a device that offers NFS 3 only.
yum -y install nfs-utils rpcbindThen you need to activate then via systemctl
systemctl enable nfs-server systemctl enable rpcbindOnly for RHEL 7.0. Starting from 7.1 this is not needed as tthe daemon below are the dependencies of nfs-server
systemctl enable nfs-lock # From RHEL 7.1 on, it is not necessary to enable nfs-lock.service manually. This service will be started automatically, if needed. systemctl enable nfs-idmap # Same as above
According to to Enable service `nfs-lock` results in error- No such file or directory - Red Hat Customer Portal since RHEL7.1 "the nfs-utils get an update to version 1.3.0-0.8.el7. By this, the nfs-lock.service is defined as dependency of rpc-bind.target. So manual enabling service is impossible now. The service is started automatically, if needed."
Start all the services
# systemctl start rpcbind # systemctl start nfs-serverOnly for RHEL 7.0. Starting from 7.1 this is done automatically as dependencies of nfs-server
# systemctl start nfs-lock # systemctl start nfs-idmapAfter that you need to check the status of nfs
systemctl status nfs-server systemctl status rpcbind
You can also check the netstat output for listening TCP and UDP ports. At this point nmap from any client should show NFS running.
Unlike Solaris and other classic Unixes, RHEL does not use share command. Instead it uses the file /etc/exports which controls which file systems are exported to remote hosts and specifies mode of this export.
The syntax is pretty typical: blank lines are ignored, comments can be made by starting a line with the hash mark (#), and long lines can be wrapped with a backslash (\).
Each line for an exported file system should has the following structure:
<exportred_directory> <host1>(<options>) <hostN>(<options>)...
As you see, each exported file system should be on its own individual line, and any lists of authorized hosts placed after an exported file system must be separated by space characters. Options for each of the hosts must be placed in parentheses directly after the host identifier, without any spaces separating the host and the first parenthesis.
In this structure, replace <export> with the directory being exported, replace <host1> with the host or network to which the export is being shared, and replace (<options> with the options for that host or network. Additional hosts can be specified in a space separated list. For example:
/sge server.example.com(options) /home/joeuser 10.194.137.1.0/24(rw) /Apps 10.194.186.254(rw,no_root_squash) 10.194.186.224(rw,no_root_squash)
The following methods can be used to specify host names:
NOTE: Wildcards are not to be used with IP addresses; however, it is possible for them to work accidentally if reverse DNS lookups fail.
Be careful when using wildcards with fully qualified domain names, as they tend to be more exact than expected. For example, the
use of *.example.com as wildcard allows sales.example.com to access an exported file system, but not bob.sales.example.com.
To match both possibilities both *.example.com and *.*.example.com must be specified.
In its simplest form, /etc/exports need only specify the exported directory and the hosts permitted to access it, as in the following example:
In the example, bob.example.com can mount /exported/directory/. Because no options are specified in this example, the following default NFS options take effect:
Once you configure NFS server and have an /etc/exports file setup, you can use systemctl to to tell the NFS server processes to reread the config and export all file systems specified in the /etc/exports file. Or you can use exportfs command:
[root@centos-7 ~]# exportfs -a
- The command exportfs -v lists the currently exported NFS shares on the server. This command will also show the default permissions applied to the NFS share.
- Use the showmount -e command to find out which shares are available.
- Use netstat -an | grep your.nfs.server.ip:port to verify the availability of the mount.
By default, access control lists (ACLs) are supported by NFS under RHEL. To disable this feature, specify the no_acl option when exporting the file system. For more about this feature, refer to the chapter titled Network File System (NFS) in the RHEL System Administration Guide.
Each default for every exported file system must be explicitly overridden. For example, if the rw option is not specified, then the exported file system is shared as read-only. The following is a sample line from /etc/exports which overrides two default options:
In this example 192.168.0.3 can mount /Apps read/write and all transfers to disk are committed to the disk before the write request by the client is completed.
Additionally, other options are available where no default value is specified. These include the ability to disable sub-tree checking, allow access from insecure ports, and allow insecure file locks (necessary for certain early NFS client implementations). Refer to the exports man page for details on these lesser used options.NOTES:
The format of the /etc/exports file is very precise, particularly in regards to use of the space character. Remember to always separate exported file systems from hosts and hosts from one another with a space character. However, there should be no other space characters in the file except on comment lines.
For example, the following two lines do not mean the same thing:/home node25.example.com(rw) /home node25.example.com (rw)
The first line allows only users from node25.example.com read/write access to the /home directory. The second line allows users from node25.example.com to mount the directory read-only (the default), but the rest of the world can mount it read/write.
For detailed instructions on configuring an NFS server by editing /etc/exports, refer to the chapter titled Network File System (NFS) in the RHEL System Administration Guide.
To restart those two daemons use the command:
systemctl restart nfs
If the firewall is enabled, ports for NFS will need to be opened.
You can also use
netstat -an | grep your.nfs.server.ip:port
to verify the availability of the mount.
From the client you can use nmap to see if NFS is available on the server.
Every file system being exported to remote users via NFS, as well as the access level for those file systems, are listed in the /etc/exports file. When the nfs service starts, the /usr/sbin/exportfs command launches and reads this file, and passes to rpc.mountd and rpc.nfsd the file systems available to remote users.
When issued manually, the /usr/sbin/exportfs command allows the root user to selectively export or unexport directories without restarting the NFS service. When passed the proper options, the /usr/sbin/exportfs command writes the exported file systems to /var/lib/nfs/xtab. Since rpc.mountd refers to the xtab file when deciding access privileges to a file system, changes to the list of exported file systems take effect immediately.
The following is a list of commonly used options available for /usr/sbin/exportfs:
If no options are passed to the /usr/sbin/exportfs command, it displays a list of currently exported file systems.
For more information about the /usr/sbin/exportfs command, refer to the exportfs man page.
Google matched content
How To Setup NFS Server on CentOS 7 - RHEL 7 - Centos-Redhat
Configure NFS Server and Client in CentOS-RHEL 7 - CentLinux
Steps to configure NFS server & client in RHEL-CentOS 7-8 - GoLinuxCloud
Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers : Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism : The Iron Law of Oligarchy : Libertarian Philosophy
War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda : SE quotes : Language Design and Programming Quotes : Random IT-related quotes : Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce : Bernard Shaw : Mark Twain Quotes
Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 : Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law
Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds : Larry Wall : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS : Programming Languages History : PL/1 : Simula 67 : C : History of GCC development : Scripting Languages : Perl history : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history
The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month : How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Haters Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite
Most popular humor pages:
Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor
The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D
Copyright © 1996-2020 by Softpanorama Society. www.softpanorama.org was initially created as a service to the (now defunct) UN Sustainable Development Networking Programme (SDNP) without any remuneration. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.
FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.
This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...
|You can use PayPal to to buy a cup of coffee for authors of this site|
Last modified: December 17, 2020