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 easiest method, and recommended, method.
• 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.

See NIS+ Administration for information on how to remove an NIS+ directory or domain, an NIS+ server, or the NIS+ namespace.

Prerequisites for Installing and Configuring NIS+

Before you start to set up NIS+ at your site, you need to

1. Plan your NIS+ layout. See Planning Your NIS+ Layout and use the planning worksheets in Configuration Worksheets. See Moving from NIS to NIS+ for a complete description of the planning process.
2. Prepare your existing namespace (if any). See Preparing the Existing Namespace.
3. Choose a root domain name.
4. Choose a root server machine.
5. 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. (Machines usually come with root in the system files, so this should not be a problem.)

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:

• 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 have to do any planning to work through the tutorial in Setting Up NIS+ With Scripts. You just need a few networked machines to practice on. But be sure to plan your site's hierarchy before you move from the tutorial to setting up your real NIS+ namespace.

Determining Server Requirements

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

NIS+ requires you to assign at least one server, the master, to each NIS+ domain. Although you can assign any number of replicas to a domain, more than 10 per domain is not recommended. An NIS+ server is capable of supporting more than one domain, but this is not recommended except in small namespaces or testing situations. 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 can obtain information from the NIS+ tables, but changes to the original 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

Disk space requirements depend on four factors:

• Disk space consumed by the Solaris 2.5 software
• Disk space for /var/nis (and /var/yp)
• Amount of memory
• Swap space required for NIS+ processes

The base AIX Version 4.3.3 software requires at least 32 MBs of disk space. You should also count the disk space consumed by other software the server may use. For more details on the base operating system installation and requirements, see the AIX Version 4.3 Installation Guide.

Although NIS+ is part of the AIX Version 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 KBs of disk space per client. For example purposes only, if a namespace has 1000 clients, /var/nis requires about 5 MBs 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 MBs is recommended. In other words, for 1000 clients, allocate 15 to 20 MBs for /var/nis. You can reduce this if you checkpoint transaction logs regularly. You should create a separate file system for /var/nis on the servers. This separate file system will help during an operating system upgrade.

If you are going to load information into NIS+ from NIS maps, allocate an appropriate amount of space for /var/yp to hold those NIS maps.

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 as 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. See Configuring a Client as an NIS+ Server and the rpc.nisd documentation for more information.

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 if you like. (You can change it later to a hierarchical structure.) Read before you start your transition from NIS to NIS+ for important planning and preparation information. The NIS+ scripts easily enable you to start NIS+ with data from NIS maps. Setting Up NIS+ With Scripts, shows you how to use the NIS+ scripts to create a NIS+ namespace from either system files or NIS maps.

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

For your reference, 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, you do not want to 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 containing a dot. Before converting to NIS+ (before running the scripts) you must eliminate any dots in your host names. You should convert host name dots to hyphens. For example, you cannot have a machine named sales.alpha. You can convert that name 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. That is easier than trying to load incomplete or damaged entries.

Configuration Worksheets

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