NFS

Automount:

Master map file

 # cat /etc/auto_master
 # local mount point  map name        mount options
 # All machines listed in /etc/hosts are automatically mounted (a subdirectory) under /net
 /net                 -hosts          -nosuid
 # directories listed in /etc/auto_home is mounted under /home (Indirect Map)
 /home                auto_home
 # Direct map file
 /-                   auto_direct
 # comment out if you use NIS+ and centrally maintained files
 #+auto_master

Indirect Map file
An Indirect map configuration file lists the pathnames and relative mount points, /home in this case

 # cat /etc/auto_home
 #key    Mount_Options     Location
 user_1                    mach_1:/export/home/user_1
 user_2                    mach_2:/export/home/user_2
 user_3                    mach_3:/export/home/user_3

The above can be replace by a single line like bellow

 *       mach_3:/export/home/&

In the above example, instead of mounting user home directories on /home/user_1 to mount on /home/users/user_1, add the following line in the auto_home file

 #key    Mount_Options   Location
 user_1     /users       mach1:/export/home/user_1

Direct Map files

 # cat auto_direct
 /home/research  -rw     filbert:/home/research

NFS mount options

 rw ro   --> read write / read only
 bg|fg   --> Try in the background / foreground if the mount attempt fails 
 retry=n  --> number of times to retry the mount operation
 port=<number> -- Set server UDP/TCP port number to <number>. Default is 2049
 proto=<udp|tcp>
 soft|hard --> Return an error if the server does not respond / or continue till the server responds
 intr|noinrt --> Allow keyboard interrupts to kill a process on a hung hard mounted file system

exportfs options

 ro  --> read only  access
 rw=host1:host2: --> read write access to host1 and host2
 anon=uid --> use "uid" as the effective user if the request comes from unknown UID
 root=host1:host2 --> Give root access to the root users from host1 and host2

TIP:
Problem: Can not change the ownership of files in NFS mounted directory
Solution: This problem occurs usually with NFS ver 4.0. NFS V.4 needs the the user name to be present both on the server and client. Otherwise, it will not let you chage the owner ship of files. We can overcome this problem by mounting the file systems as nfs v.3.

In Solaris:

 # mount - nfs -o rw,vers=3 server:<directory> /<mount_point>

In Linux

 # mount -o rw,nfsvers=3  server:<directory> /<mount_point>