Cvsup and RELENG_4 or RLENG_4_9

Erik Trulsson ertr1013 at
Sun Feb 1 14:07:11 PST 2004

On Sun, Feb 01, 2004 at 04:07:46PM -0500, Bob Collins wrote:
> I have read through the keeping current section of the book a few times
> and I am a bit lost. If I read correctly, to upgrade source(I am running
> RELEASE-4.9) I can use either RELENG_4 or RELENG_4_9. Although I am not
> sure if I need one, the other, or both. And if both, which order, if it
> matters?

You should use one of them - not both.

> Further reading indicates that cvsuping with RLENEG_4_9 will update only
> critical items. Again, if I am reading this correctly, should I then
> cvsup both so I have all the sources corrected, or is RELENG_4_9 enough
> for a production machine?

Either RELENG_4 or RELENG_4_9 will get you complete sources.
The differences is that RELENG_4 is the development branch leading up
to the next 4.x release, while RELENG_4_9 is essentially 4.9-RELEASE +
critical fixes. (With 4.9-RELEASE being essentially a snapshot of the
RELENG_4 branch at a particular moment in time.)

RELENG_4 can potentially contain a large number of differences from
4.9-RELEASE, while RELENG_4_9 will only have minor (if any) differences
to the sources used for 4.9-RELEASE.

> Thanks for your patience with this. I have also searched a bit about it
> and I am on the right track, I just think I need some clarification as
> to which one is `best' for a production machine.
> FWIW, this will be for a dual processed server.

RELENG_4_9 is much less likely to introduce *new* bugs to the code, but
it will not get all the bugfixes or new features that get added to
Most of the time RELENG_4 (aka 4-STABLE) is quite stable and safe, but
occasionaly things break badly. (An example of that is back in August
2003, when RELENG_4 was quite unstable and crash-prone for a period of
about three weeks, until a bug had been fixed that had been introduced
when support for machines with more than 4GB RAM had been added.)

If you currently do not have any problems with 4.9-RELEASE and follow
the "if it ain't broke don't fix it" school of thought then RELENG_4_9
is probably right for you.

Personally I use RELENG_4, but then it is not crucial that my machines
stay up all the time, so if they crash due to some new bug introduced
in RELENG_4 it is not a major catastrophy.

<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at

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