NIS+ Transition Guide

Determining Server Requirements

Each NIS+ domain is supported by a set of NIS+ servers. Each set contains one master and one or more replica servers. These servers store the domain's directories, groups, and tables, and answer requests for access from users, administrators, and applications. Each domain is supported by only one set of servers. While a single set of servers can support more than one domain, this is not recommended.

The NIS+ service requires you to assign at least one server, the master, to each NIS+ domain. How many replica servers a domain requires is determined by the traffic load, the network configuration, and whether NIS clients are present. The amount of server memory, disk storage, and processor speed is determined by the number of clients and the traffic load they place on the servers.

Any workstation, running in the Solaris operating environment, can be an NIS+ server, as long as it has its own hard disk of sufficient size. The software for both NIS+ servers and clients is included in the Solaris product. Therefore, any workstation that has the Solaris operating environment installed can become a server or a client, or both.

When determining what servers are needed to support your NIS+ namespace, consider these factors, discussed in the following sections:

Number of Supported Domains

To begin, you assign one master server to each domain in the hierarchy. Figure 2-4 shows one possible assignment.

Figure 2-4 Assigning Servers to Domains


Add one or more replicas to each domain. Replicas allow requests to be answered even if the master server is temporarily out of service. (See "Designing the Namespace Structure" for information on how many replicas to use.)

Figure 2-5 Adding Replicas to a Domain


Number of Replica Servers

The optimum number of servers (master plus replicas) for a domain is determined by a number of factors:

One way you can have a sufficient number of replicas per domain without using a multiplicity of machines is to create multihomed servers. A multihomed server is a machine with multiple ethernet or network interfaces. A multihomed server can serve multiple subnets in a domain. (While it is possible to have a master or replica serve multiple domains, that is not recommended.)

Server Speed

The faster the server, the better NIS+ performs. (However, at this time NIS+ servers cannot take advantage of SMP multithreaded hardware.) Your NIS+ servers should be as powerful, or more powerful, than your average client. Using older machines as servers for newer clients is not recommended.

In addition to server speed, many other factors affect NIS+ performance. The numbers and kinds of users and hosts, the kinds of applications being run, network topology, load densities, and other factors, all affect NIS+ performance. Thus, no two networks can expect identical performance from the same server hardware.

The benchmark figures presented in Table 2-2 below, are for comparison purposes only; performance on your network may vary. These benchmark figures are based on a test network with typical table sizes of 10,000 entries. See Table 2-2.

Table 2-2 Hardware Speed Comparison NIS+ Operations


Number of Match Operations Per Second 

Number of Add Operations Per Second 

 SS5-110 400 6
 SS20-50 440 6
 PPro-200 760 13
 Ultra-167 800 11
 Ultra-200 1270  8

Server Memory Requirements

Although 32 Mbytes is the absolute minimum memory requirement for servers, it is better to equip servers of medium-to-large domains with at least 64 Mbytes.

Ideally, an NIS+ server should have enough memory to hold all the entries of all the searchable columns of all the operative NIS+ tables in RAM at one time. In other words, optimal server memory is equal to the total memory requirements of all the NIS+ tables.

For illustration purposes, Table 2-3 shows memory requirements for the netgroup table with five searchable columns, and Table 2-4 shows approximate memory requirements for the passwd, host, and cred tables.

Table 2-3 Server Memory Required for netgroups Table

Number of Entries 

Server Memory Usage in Mbytes 

 6,000 4.2
 60,000 39.1
 120,000 78.1
 180,000 117.9
 240,000 156.7
 300,000 199.2

Table 2-4 Approximate Memory Required for passwd Table

Number of Entries 

Server Memory Usage in Mbytes 

 6,000 3.7
 60,000 31.7
 120,000 63.2
 180,000 94.9
 240,000 125.8
 300,000 159.0
 1,000,000 526.2

For the other tables, you can estimate the memory size by multiplying the estimated number of entries times the average number of bytes per entry for each searchable column. For example, suppose you have a table with 10,000 entries and two searchable columns. The average number of bytes per entry in the first column is 9, the average number of bytes per entry in the second column is 37. Your calculation is: (10,000x9)+(10,000x37)=460,000.

Note -

When estimating the number of entries in the cred table, keep in mind that every user will have two entries (one for the user's Local credential and one for the user's DES credential). Each machine will have only one entry.

See "NIS+ Standard Tables" for the number of searchable columns in each of the standard NIS+ tables.

Server Disk Space Requirements

How much disk space you need depends on four factors:

The Solaris operating environment can require over 220 Mbytes of disk space, depending on how much of it you install. For exact numbers, see your Solaris installation guides. You should also count the disk space consumed by other software the server might use. The NIS+ software itself is part of the Solaris 2.6 distribution, so it does not consume additional disk space.

NIS+ directories, groups, tables, and client information are stored in /var/nis. The /var/nis directory uses about 5 Kbytes of disk space per client. For example purposes only, if a namespace has 1000 clients, /var/nis requires about 5 Mbytes 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 Mbytes is recommended. In other words, for 1000 clients, allocate 15 to 20 Mbytes for /var/nis. You can reduce this if you checkpoint transaction logs regularly. You should also create a separate partition for /var/nis. This separate partition will help during an operating system upgrade.

If you will 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 twice the size of rpc.nisd--in addition to the server's normal swap space requirements. To see the amount of memory being used by rpc.nisd on your system, run the nisstat command. See the rpc.nisd man page for more information. 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. In no case should you use less than 64 Mbytes of swap space.