http://www.tug.org/texlive/doc/texlive-en/live.html
texconfig help
Output help information for texconfig.
Of course, texconfig can only support changing a few of the many options and configuration parameters in a TEX system. The main configuration file for the base Web2C programs is named texmf.cnf. You can find its location by running ‘kpsewhich texmf.cnf’; it contains many comments explaining the default settings and useful alternatives.
texconfig alters files in a user-specific directory, as in $HOME/.texlive2007. If you install TEX just for yourself, that is unlikely to make a difference. But if you install TEX on a multi-user system, you will want to change the configuration for the whole system. In this case, run texconfig-sys instead of texconfig.
Likewise, the updmap and fmtutil scripts were changed, to work under $HOME/.texliveYYYY. To alter system directories, use updmap-sys and fmtutil-sys.
In particular, for multi-user systems, you will probably want to pregenerate the standard formats with fmtutil-sys –missing. Otherwise, each user will end up with their own formats.
Also, if you have a personally-modified copy of fmtutil.cnf or updmap.cfg, instead of using the ones generated by installation, they must be installed in the tree referenced by the variable TEXMFSYSCONFIG.
