Before building a package, you need to decide whether your product will consist of one or more packages. Note that many small packages take longer to install than one big package. Although creating a single package is a good idea, doing so is not always possible. If you decide to build more than one package, you need to determine how to segment the application code. This section provides a list of criteria to use when planning to build a package.
Many of the packaging criteria present trade-offs among themselves. Satisfying all requirements equally is often difficult. These criteria are presented in order of importance. However, this sequence is meant to serve as a flexible guide depending on the circumstances. Although each criterion is important, it is up to you to optimize these requirements to produce a good set of packages.
For more design ideas, see Chapter 6, Advanced Techniques for Creating Packages.
All packages must be remotely installable. Being remotely installable means that the administrator installing your package might be trying to install it on a client system, not necessarily to the root (/) file system where the pkgadd command is being executed.
Consider the various types of system software configurations (for example, standalone system and server) when laying out packages. Good packaging design divides the affected files to optimize installation of each configuration type. For example, the contents of the root (/) and /usr file systems should be segmented so that server configurations can easily be supported.
Packages should be self-contained and distinctly identified with a set of functionality. For example, a package that contains UFS should contain all UFS utilities and be limited to only UFS binaries.
Packages should be organized from a customer's point of view into functional units.
Put code that requires royalty payments due to contractual agreements in a dedicated package or group of packages. Do not disperse the code into more packages than necessary.
Keep system-dependent binaries in dedicated packages. For example, the kernel code should be in a dedicated package, with each implementation architecture consisting of a distinct package instance. This rule also applies to binaries for different architectures. For example, binaries for a SPARC system would be in one package and binaries for an x86 system would be in another package.
When constructing packages, eliminate duplicate files whenever possible. Unnecessary duplication of files results in support and version difficulties. If your product has multiple packages, repeatedly compare the contents of these packages for duplicated files.
Localization-specific items should be in their own package. An ideal packaging model would have a product's localizations delivered as one package per locale. Unfortunately, in some cases organizational boundaries conflict with the functional and product boundaries criteria.
International defaults can also be delivered in a package. This design isolates the files that are necessary for localization changes and standardizes the delivery format of localization packages.