*BSD News Article 61427


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!newsroom.utas.edu.au!munnari.OZ.AU!spool.mu.edu!howland.reston.ans.net!Germany.EU.net!Hanover.Germany.EU.net!Hamburg.Germany.EU.net!nuki.NetUSE.de!tpki.toppoint.de!rimki.toppoint.de!chrimek
Date: 15 Feb 1996 13:13:00 +0100
From: chrimek@rimki.toppoint.de (Christoph Rimek)
Newsgroups: comp.unix.bsd.netbsd.misc
Message-ID: <62v6SxqZo$B@rimki.toppoint.de>
Subject: How compatible should kernel be?
X-Newsreader: CrossPoint v3.1 R/C6513
Organization: Toppoint Mailbox e.V.
Reply-To: chrimek@toppoint.de
Lines: 59

Hello

After my posting of yesterday concerning the filesystems, here I have
some more questions that deal with some of the option to specify for new
kernels to be build.

How compatible should a kernel be, and compatible to what?
There are the options:

    COMPAT_NOMID        accept non-valid machine ID binaries
                        (BSDI, 386BSD, NetBSD 0.8)
    COMPAT_09           be compatible to NetBSD release 0.9
    COMPAT_10           be compatible to NetBSD releaes 1.0

I started using NetBSD with the 1.0 release, so there are no old binary
packages that I have to support.
Currently I use (for the 1.1 version) the COMPAT_10 option only, and
found no disadvantages. What reasons do I need the other two options for?

    COMPAT_43           4.3 BSD compatible system calls
    TCP_COMPAT_42       use 4.2 BSD style TCP

IMO the first should be enabled, although I cannot clearly say why.
The latter should never be used unless you really have to, as Craig Hunt
states in his book "TCP/IP Network Administration" (O'Reilly).

One other section manages the inter-process communication (IPC), and I
think one has to decide locally whether one wants the SystemV-style
behaviour supported or not: SYSVMSG, SYSVSEM, SYSVSHM, and since 1.1
the additional SHMAXPGS=<value> .
Until now I compiled all my kernels (1.0 and up) with these options  
disabled.

The same is valid for another group, the binary compatibility to other
Unix versions/implementations.
There are COMPAT_SVR4, COMPAT_IBCS2, COMPAT_LINUX and COMPAT_FRREBSD.
If I do not exchange precompiled packages from one system to another
there is no reason for any of these options, IMO.

Do I need any of these options if I'd like to have a pure BSD system?
Until now I do not use any of these, and I found no drawbacks so far.

The system I have in mind works as the main mail server for a small
department (60 users), and today it has an uptime of 66 days without
any trouble.


On the other hand there are a few options that are absolutely required
for all machines or for specific architectures.
I'd like to have a comprehensive description for all possible options
and maybe a guide that helps me to decide, which option I do need and
which one I can leave out.


Any comments welcome.
-cr

--
Christoph Rimek, Kiel, Germany  (+49 431 57601)      chrimek@toppoint.de