Default Configuration of NFS

NFS is not difficult to configure because there are not as many options as FTP or SMB have. The /etc/exports file contains a table of physical filesystems on an NFS server accessible by the clients. The NFS Exports Table shows which options it accepts and thus indicates which options are available to us.

Exports File

NFS

z3tssu@htb[/htb]$ cat /etc/exports 

# /etc/exports: the access control list for filesystems which may be exported
#               to NFS clients.  See exports(5).
#
# Example for NFSv2 and NFSv3:
# /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
#
# Example for NFSv4:
# /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
# /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)

The default exports file also contains some examples of configuring NFS shares. First, the folder is specified and made available to others, and then the rights they will have on this NFS share are connected to a host or a subnet. Finally, additional options can be added to the hosts or subnets.

Option	Description
rw	Read and write permissions.
ro	Read only permissions.
sync	Synchronous data transfer. (A bit slower)
async	Asynchronous data transfer. (A bit faster)
secure	Ports above 1024 will not be used.
insecure	Ports above 1024 will be used.
no_subtree_check	This option disables the checking of subdirectory trees.
root_squash	Assigns all permissions to files of root UID/GID 0 to the UID/GID of anonymous, which prevents root from accessing files on an NFS mount.