Network File System
From Oxxus Wiki
This file system management feature, NFS, has the ability to manage file system remotely, over network, as well as via Internet or Intranet. It allows for fast, seamless sharing of files across a network.
You'll find a complete, step-by-step guide below to setting up NFS. Setting up NFS involves configuring the server and then configuring the client.
Setting up the Configuration Files
Three main configuration files, /etc/exports, /etc/hosts.allow, and /etc/hosts.deny, will need to be configured for NFS server.
Configuration involves editing files, adjusting contents and saving changes. Any editor, like nano can be used.
An entry in /etc/exports will usually look like this:
directory machine1(option11,option12) machine2(option21,option22)
- the directory that you want to share
- machine1 and machine2
- client machines that will have access to the directory
- ro - the directory is shared read only,
- rw - the client machine will have read and write access to the directory.
Here's a working example below.
A typical setup for /etc/exports might look like this:
/usr/local 192.168.0.1(ro) 192.168.0.2(ro) /home 192.168.0.1(rw) 192.168.0.2(rw)
Here we are sharing /usr/local read-only to slave1 with ip 192.168.0.1 and slave2 with ip 192.168.0.2.
/etc/hosts.allow and /etc/hosts.deny
These two files specify which computers on the network can use services on your machine.
The first step in doing this is to add the followng entry to /etc/hosts.deny:
Secondly, you need to add an entry to hosts.allow to give any hosts access that you want to have access.
service: host [or network/netmask] , host [or network/netmask]
Host is IP address of a potential client.
Assuming the setup is as above, the only things to do is to allow access to slave1.foo.com and slave2.foo.com. Assumption is made that the IP addresses of these machines are 192.168.0.1 and 192.168.0.2, respectively. A following entry could be added to /etc/hosts.allow:
portmap: 192.168.0.1 , 192.168.0.2
Once configuration is set, NFS services can be started up and remote system's file will be available with permissions set in above configuration files.
NFS depends on the portmapper daemon, either called portmap or rpc.portmap.
It will need to be started first. It should be located in /sbin but is sometimes in /usr/sbin. Most recent Linux distributions start this daemon in the boot scripts, but it is worth checking that it is running before you begin working with NFS (just type ps aux | grep portmap).
For RedHat related distributions use following commands below from account's shell prompt:
/etc/init.d/portmap start /etc/init.d/nfs start
After executing these commands your system's ready for NFS services.
Verifying that NFS is running
After executing command rpcinfo quota you should get something similar:
program vers proto port 100000 2 tcp 111 portmapper 100000 2 udp 111 portmapper 100011 1 udp 749 rquotad 100011 2 udp 749 rquotad 100005 1 udp 759 mountd 100005 1 tcp 761 mountd 100005 2 udp 764 mountd 100005 2 tcp 766 mountd 100005 3 udp 769 mountd 100005 3 tcp 771 mountd 100003 2 udp 2049 nfs 100003 3 udp 2049 nfs 300019 1 tcp 830 amd 300019 1 udp 831 amd 100024 1 udp 944 status 100024 1 tcp 946 status 100021 1 udp 1042 nlockmgr 100021 3 udp 1042 nlockmgr 100021 4 udp 1042 nlockmgr 100021 1 tcp 1629 nlockmgr 100021 3 tcp 1629 nlockmgr 100021 4 tcp 1629 nlockmgr
Making Changes to /etc/exports later on
If you need to change your /etc/exports file, the changes you make may not take effect immediately. You should run the command exportfs -ra to force nfsd to re-read the /etc/exports file. If you can't find the exportfs command, then you can kill nfsd with the -HUP flag.