Explain the NFS server configuration files.

61.Explain the NFS server configuration files.
Ans.
1. The server configuration file is ‘/etc/exports’, which contains a list of file system to export, the clients permitted to mount them and several export options that apply to client mounts.

2. Each line in ‘/etc/exports’ has following syntax:
Dir [Host] (option)[….]
Dir specifies one or more mount options
Host specifies one or more mount options.

3. If user omits host, the listed options apply to every possible client system and if options are omitted then the default mount options will be applied.

4. Consider the sample of ‘/etc/exports’ file as follows:
a) /usr/share *.mu.ac.in(ro)
It permitsall host on mu.ac.in to mount /usr/share as read only directory.
b) ./courses/tyit 192.168.166.0/24 (rw)
It uses the address/netmask form in which the net mask is specified in classless Inter-Domain Routing (CIDR) format.
c) /home 192.168.0.0/255.255.255.0 (rw)
It permits any host with an IP address in the range 192.168.166.0 to 192.168.166.254 to mount /home in read-write mode.
d) /projects @dev (rw)
It permits any member of NIS net group named dev to mount /projects
e) /var/spool/mail 192.168.166.12 (rw)
It permits only the host whose IP address is 192.168.166.12 to mount /var/mail
f) /opt/kde gss/krbs (ro)
Any host using RPCSEC-GSS security to mount /opt/kde in read only mode.