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 the table 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.
Table 26-2 Hardware Speed Comparison NIS+ Operations
Machine | 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, the table below shows memory requirements for the netgroup table with five searchable columns, and Table 26-4 shows the approximate memory requirements for the passwd, t, and cred tables.
Table 26-3 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 26-4 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:
Disk space consumed by the Solaris operating environment.
Disk space for /var/nis (and /var/yp if using NIS compatibility).
Amount of server memory.
Swap space required for NIS+ server processes.
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 operating environment 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.
Determining Table Configurations
NIS+ tables provide several features not found in simple text files or maps. They have a column-entry structure, accept search paths, can be linked together, and can be configured in several different ways. You can also create your own custom NIS+ tables. When selecting the table configurations for your domains, consider the following factors discussed in the following sections:
Differences Between NIS+ Tables and NIS Maps
NIS+ tables differ from NIS maps in many ways, but two of those differences should be kept in mind during your namespace design:
NIS+ uses fewer standard tables than NIS.
NIS+ tables interoperate with /etc files differently than NIS maps did in the SunOS 4.x releases.
NIS+ Standard Tables
Review the 17 standard NIS+ tables to make sure they suit the needs of your site. They are listed in "NIS+ Standard Tables". Table 26-6 lists the correspondences between NIS maps and NIS+ tables.
Do not worry about synchronizing related tables. The NIS+ tables store essentially the same information as NIS maps, but they consolidate similar information into a single table (for example, the NIS+ hosts table stores the same information as the hosts.byaddr and hosts.byname NIS maps). Instead of the key-value pairs used in NIS maps, NIS+ tables use columns and rows. (See Table 26-6.) Key-value tables have two columns, with the first column being the key and the second column being the value. Therefore, when you update any information, such as host information, you need only update it in one place, such as the hosts table. You no longer have to worry about keeping that information consistent across related maps.
Note the new names of the automounter tables:
auto_home (old name: auto.home)
auto_master (old name: auto.master)
The dots were changed to underscores because NIS+ uses dots to separate directories. Dots in a table name can cause NIS+ to mistranslate names. For the same reason, machine names cannot contain any dots. You must change any machine name that contains a dot to something else. For example, a machine named sales.alpha is not allowed. You could change it to sales_alpha or salesalpha or any other name that does not contain a dot.
To make the transition from NIS to NIS+, you must change the dots in your NIS automounter maps to underscores. You may also need to do this on your clients' automounter configuration files. Refer to the following table:
Table 26-5 NIS+ Tables
NIS+ Table | Information in the Table |
|---|---|
hosts | Network address and host name of every machine in the domain |
bootparams | Location of the root, swap, and dump partition of every diskless client in the domain |
passwd | Password information about every user in the domain |
cred | Credentials for principals who belong to the domain |
group | The group password, group ID, and members of every UNIX® group in the domain |
netgroup | The netgroups to which machines and users in the domain may belong |
mail_aliases | Information about the mail aliases of users in the domain |
timezone | The time zone of the domain |
networks | The networks in the domain and their canonical names |
netmasks | The networks in the domain and their associated netmasks |
ethers | The ethernet address of every machine in the domain |
services | The names of IP services used in the domain and their port numbers |
protocols | The list of IP protocols used in the domain |
rpc | The RPC program numbers for RPC services available in the domain |
auto_home | The location of all user's home directories in the domain |
auto_master | Automounter map information |
sendmailvars | Stores the mail domain |
Table 26-6 Correspondences Between NIS Maps and NIS+ Tables
NIS Map | NIS+ Table | Notes |
|---|---|---|
auto.home | auto_home | |
auto.master | auto_master | |
bootparams | bootparams | |
ethers.byaddr | ethers | |
ethers.byname | ethers | |
group.bygid | group | Not the same as NIS+ groups |
group.byname | group | Not the same as NIS+ groups |
hosts.byaddr | hosts | |
hosts.byname | hosts | |
mail.aliases | mail_aliases | |
mail.byaddr | mail_aliases | |
netgroup | netgroup | |
netgroup.byhost | netgroup | |
netgroup.byuser | netgroup | |
netid.byname | cred | |
netmasks.byaddr | netmasks | |
networks.byaddr | networks | |
networks.byname | networks | |
passwd.byname | passwd | |
passwd.byuid | passwd | |
protocols.byname | protocols | |
protocols.bynumber | protocols | |
publickey.byname | cred | |
rpc.bynumber | rpc | |
services.byname | services | |
ypservers | Not needed |