On 12/11/2012 06:35 AM, Tom H wrote:
> You probably looked at the ifup script and not its man page because 
> the latter's pretty bare. "/usr/share/doc/initscripts-*/sysconfig.txt" 
> is more or less complete but I've found it lacking from time to time - 
> and then it catches up. For example, in initscripts-9.03.31 (and 
> perhaps in an earlier version too) it documents "NM_CONTROLLED". 

In double-checking, no, I can grok it from just the man page.  Quoting:

>        The  ifup  and  ifdown  commands  may be used to configure (or, 
> respec-
>        tively, deconfigure) network interfaces based on interface  
> definitions
>        in   the   files   /etc/sysconfig/network  and  
> /etc/sysconfig/network-
>        scripts/ifcfg-<configuration>

Reading between the lines, yes, but even a cursory reading of the config 
files is enough to make me ask 'hmm, can I set a variable in 
/etc/sysconfig/network that is normally defined in the ifcfg file, and 
which definition will override?'  Obviously, the actual scripts' 
behavior documented by the script itself trumps it, but reading the 
source isn't necessary; of course, that assumes that the documentation 
really is correct.

At least with NM_CONTROLLED it actually does work that way.  Other items 
could obvoiusly be special-cased in the scripts' sources, of course.