Specifications

Chapter 4 NFS Service 71
NFS allows access to information based on the computer’s IP address. This means that a
particular client computer will have access to certain share points regardless of who is
using the computer. Whenever that computer is started up, some volumes or folders
are automatically mounted or made available, and anyone using that computer can
access those volumes or folders.
With NFS, it’s possible for a user to spoof ownership of another person’s files. For
example, if a file on the server is owned by a user with user ID 1234, and you export a
folder that contains that file, someone on a remote computer can create a local user on
the remote computer, give it a user ID of 1234, mount that folder, and have the same
access to the folder’s contents as the file’s original owner.
You can take some steps to prevent this by creating unique user IDs and by
safeguarding user information. If you have Internet access and plan to export to World,
your server should be behind a firewall.
Setting Up NFS Service
You can use Server Admin to change some NFS service settings.
Configuring NFS Settings
The NFS settings let you set the maximum number of daemons and choose how you
want to serve clients—via TCP, UDP, or both.
To configure NFS settings:
1 Open Server Admin and select NFS in the Computers & Services list.
2 Click Settings (near the bottom of the window).
3 Type a number in the “Use__server daemons” field to specify the maximum number of
nfsd daemons you want to allow to run at one time.
An nfsd daemon is a server process that runs continuously behind the scenes and
processes reading and writing requests from clients. The more daemons that are
available, the more concurrent clients can be served. Typically, four to six daemons are
adequate to handle the level of concurrent requests.
4 Choose how you want to serve data to your client computers.
Select both TCP and UDP unless you have a specific performance concern. TCP provides
better performance for clients, and UDP puts a smaller load on the server.
Transmission Control Protocol (TCP) separates data into packets (small bits of data sent
over the network using IP) and uses error correction to make sure information is
transmitted properly.