2 Distribution Format

A typical FreeBSD distribution directory looks something like this (exact details may vary depending on version, architecture, and other factors):

ERRATA.HTM      README.TXT      compat1x        dict            kernel
ERRATA.TXT      RELNOTES.HTM    compat20        doc             manpages
HARDWARE.HTM    RELNOTES.TXT    compat21        docbook.css     packages
HARDWARE.TXT    base            compat22        filename.txt    ports
INSTALL.HTM     boot            compat3x        floppies        proflibs
INSTALL.TXT     catpages        compat4x        games           src
README.HTM      cdrom.inf       crypto          info            tools

These same files are contained in the first CDROM of a multi-disk set, but they are laid out slightly differently on the disk. On most architectures, the installation CDROM also contains a “live filesystem” in addition to the distribution files. The live filesystem is useful when repairing or troubleshooting an existing FreeBSD installation (see Section 4 for how to use this).

The floppies directory will be of particular interest to users who are unable to boot from the CDROM media (but are able to read the CDROM by other means). It is easy to generate a set of 1.44MB boot floppies from the floppies directory (see Section 1.3 for instructions on how to do this) and use these to start an installation from CDROM, FTP, or NFS. The rest of the data needed during the installation will be obtained automatically based on your selections. If you've never installed FreeBSD before, you also want to read the entirety of this document (the installation instructions) file.

If you're trying to do some other type of installation or are merely curious about how a distribution is organized, what follows is a more thorough description of some of these items in more detail:

1. The *.TXT and *.HTM files contain documentation (for example, this document is contained in both INSTALL.TXT and INSTALL.HTM) and should be read before starting an installation. The *.TXT files are plain text, while the *.HTM files are HTML files that can be read by almost any Web browser. Some distributions may contain documentation in other formats as well, such as PDF or PostScript.

2. docbook.css is a Cascading Style Sheet (CSS) file used by some Web browsers for formatting the HTML documentation.

3. The base, catpages, crypto, dict, doc, games, info, manpages, proflibs, and src directories contain the primary distribution components of FreeBSD itself and are split into smaller files for easy packing onto floppies (should that be necessary).

4. The compat1x, compat20, compat21, compat22, compat3x, and compat4x directories contain distributions for compatibility with older releases and are distributed as single gzip'd tar files - they can be installed during release time or later by running their install.sh scripts.

5. The floppies/ subdirectory contains the floppy installation images; further information on using them can be found in Section 1.3.

6. The packages and ports directories contain the FreeBSD Packages and Ports Collections. Packages may be installed from the packages directory by running the command:

   # sysinstall configPackages
   

   Packages can also be installed by feeding individual filenames in packages/ to the pkg_add(1) command.

   The Ports Collection may be installed like any other distribution and requires about 190MB unpacked. More information on the ports collection may be obtained from http://www.FreeBSD.org/ports/ or locally from /usr/share/doc/handbook if you've installed the doc distribution.

7. Last of all, the tools directory contains various DOS tools for discovering disk geometries, installing boot managers and the like. It is purely optional and provided only for user convenience.

A typical distribution directory (for example, the info distribution) looks like this internally:

CHECKSUM.MD5    info.ab         info.ad         info.inf        install.sh
info.aa         info.ac         info.ae         info.mtree

The CHECKSUM.MD5 file contains MD5 signatures for each file, should data corruption be suspected, and is purely for reference. It is not used by the actual installation and does not need to be copied with the rest of the distribution files. The info.a* files are split, gzip'd tar files, the contents of which can be viewed by doing:

# cat info.a* | tar tvzf -

During installation, they are automatically concatenated and extracted by the installation procedure.

The info.inf file is also necessary since it is read by the installation program in order to figure out how many pieces to look for when fetching and concatenating the distribution. When putting distributions onto floppies, the .inf file must occupy the first floppy of each distribution set!

The info.mtree file is another non-essential file which is provided for user reference. It contains the MD5 signatures of the unpacked distribution files and can be later used with the mtree(8) program to verify the installation permissions and checksums against any possible modifications to the file. When used with the base distribution, this can be an excellent way of detecting trojan horse attacks on your system.

Finally, the install.sh file is for use by those who want to install the distribution after installation time. To install the info distribution from CDROM after a system was installed, for example, you'd do:

# cd /cdrom/info
# sh install.sh