Network Information Services (NIS and NIS+) Guide

Setting Up NIS+

This section describes two different methods of setting up an NIS+ namespace:

With the setup scripts--How to set up NIS+ using the three NIS+ scripts: nisserver, nispopulate, and nisclient. This is the recommended method because it is easier.
With the NIS+ command set--How to set up NIS+ using the NIS+ command set. While this method gives you more flexibility than the scripts method, it is more difficult. This method should be used only by experienced NIS+ administrators who need to set up a namespace with characteristics significantly different than those provided by the setup scripts.

Prerequisites for Installing and Configuring NIS+

Before you start setting up NIS+ at your site, you must do the following:

Plan your NIS+ layout. See Planning Your NIS+ Layout and use the Configuration Worksheets. See Chapter 3, Moving from NIS to NIS+ for a complete description of the planning process.
Prepare your existing namespace (if any). See Preparing the Existing Namespace.
Choose a root domain name.
Choose a root server machine.
Make sure that you have at least one system already running at your site that can be used as your root master server. This machine must contain at least one user (root) in the system information files, such as /etc/passwd.

To create the sample namespace, you need only do steps 2, 4, and 5 above. The tutorial does the NIS+ layout planning for you and chooses a domain name.

Planning Your NIS+ Layout

To plan the structure of your NIS+ namespace, do the following:

Determine your server requirements.
Determine your disk space and memory requirements.
Sketch the domain hierarchy.
Select servers to be used for the namespace.
Determine the administrative groups and their members.
Determine access rights to the namespace.

See Designing the NIS+ Namespace for a full description of these steps and use the Configuration Worksheets to help plan your namespace.

You do not need planning to practice the tutorial with test machines, but be sure to plan your site's hierarchy before setting up your real NIS+ namespace.

Determining Server Requirements

Once you have determined the domain structure of your namespace, choose the servers that will support them. Differentiate between the requirements imposed by NIS+ and those imposed by the traffic load of your namespace.

NIS+ requires at least one server, the master, for each NIS+ domain. Although you can assign any number of replicas to a domain, more than 10 per domain is not recommended. The number of servers a domain requires is determined by the traffic load and the configuration of its servers.

Here are some guidelines for determining how many servers you will need:

Assign one master server per domain in the hierarchy.
Add at least one replica server for each domain. (A replica can answer requests when the master is unavailable.)

Note: If the root master server is unavailable and the NIS+ domain is being served solely by a replica, you cannot change information in the NIS+ tables. You can obtain information from a replica, but changes to the master tables can be made only when the master server is available.
Calculate the disk space requirements of each server. The next section describes how to calculate disk space usage.

Evaluate Disk Space and Memory Requirements

How much disk space you need depends on four factors:

Disk space consumed by AIX 4.3.3 Base Operating System (BOS)
Disk space for /var/nis (and /var/yp)
Amount of memory
Swap space required for NIS+ server processes

AIX 4.3.3 BOS software requires at least 32 MB of disk space. You must also consider the disk space consumed by other software the server may use. For more details on the BOS installation and requirements, see the AIX Version 4.3 Installation Guide.

Although NIS+ is part of the AIX 4.3.3 distribution, it is not automatically installed in the base installation. NIS+ directories, groups, tables, and client information are stored in /var/nis. The /var/nis directory uses about 5 KB of disk space per client. For example purposes only, if a namespace has 1000 clients, /var/nis requires about 5 MB of disk space. However, because transaction logs (also kept in /var/nis) can grow large, you may want additional space per client--an additional 10-15 MB is recommended. In other words, for 1000 clients, allocate 15 to 20 MB for /var/nis. You can reduce this if you checkpoint transaction logs regularly.

If you plan to use NIS+ concurrently with NIS, allocate space equal to the amount you are allocating to /var/nis for /var/yp to hold the NIS maps that you transfer from NIS.

You also need swap space equal to three times or more of the size of the NIS+ server process--in addition to the server's normal swap-space requirements. The size of the rpc.nisd process is shown by the ps -efl command. Most of this space is used during callback operations or when directories are checkpointed (with nisping -C) or replicated, because during such procedures, an entire NIS+ server process is forked.

Preparing the Existing Namespace

If an NIS domain already exists at your site, you can use the same flat domain structure for your NIS+ namespace. (You can change it later to a hierarchical structure.) Read Chapter 3, Moving from NIS to NIS+ for important planning and preparation information. The NIS+ scripts let you start NIS+ with data from NIS maps. Using NIS+ Setup Scripts shows you how to use the NIS+ scripts to create a NIS+ namespace from either system files or NIS maps.

For the scripts to run smoothly, however, you must prepare your existing namespace (if you have one) for conversion to NIS+.

Key preparations are summarized below:

Domain and host names: Domains and hosts must not have the same name. For example, if you have a sales domain you cannot have a machine named sales. Similarly, if you have a machine named home, do not create a domain named home. This caution also applies to subdomains; for example, if you have a machine named west, do not create a sales.west.myco.com subdirectory.
No dots in host names: Because NIS+ uses dots (periods) to delimit between machine names and domains and between parent and subdomains, you cannot have a machine name that contains a dot. Before converting to NIS+ (before running the scripts) you must eliminate any dots in your host names. You can convert host name dots to hyphens. For example, sales.alpha can convert to sales-alpha.
Root server must be running: The machine that will be designated the root server must be up and running and you must have superuser access to it.
View any existing local /etc files or NIS maps that you will be loading data from.: Make sure that there are no spurious or incorrect entries. Make sure that the right data is in the correct place and format. Remove any outdated, invalid, or corrupt entries. You should also remove any incomplete or partial entries. You can always add individual entries after setup is completed.

Configuration Worksheets

If you have more than one domain, make copies of the blank worksheets.

Servers, Credentials, Directories, and Groups Worksheet
Domain:
Servers	Type	Name				Specifications
	Master
	First Replica
	Second Replica


Credentials	Type of Principal	Type of Credential
	Servers
	Clients
	Administrators
	Users
Rights	Types of Objects	Category & Rights
	Directories	N	O	G	W	Use Defaults?





	Groups	N	O	G	W	Description

NIS+ Tables Worksheet
Domain:
Rights	Types of Objects	Category & Rights
	Tables	N	O	G	W	Notes
	bootparams
	hosts
	passwd
	cred
	group
	netgroup
	mail_aliases
	timezone
	networks
	netmasks
	ethers
	services
	protocols
	rpc
	auto_home
	auto_master
	sendmailvars
	client_info