From owner-freebsd-questions@FreeBSD.ORG Sun Dec 10 20:45:27 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 2747B16A51A for ; Sun, 10 Dec 2006 20:45:27 +0000 (UTC) (envelope-from youshi10@u.washington.edu) Received: from mxout3.cac.washington.edu (mxout3.cac.washington.edu [140.142.32.166]) by mx1.FreeBSD.org (Postfix) with ESMTP id E81D643CBF for ; Sun, 10 Dec 2006 20:44:04 +0000 (GMT) (envelope-from youshi10@u.washington.edu) Received: from smtp.washington.edu (smtp.washington.edu [140.142.32.139]) by mxout3.cac.washington.edu (8.13.7+UW06.06/8.13.7+UW06.09) with ESMTP id kBAKjGBH006797 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 10 Dec 2006 12:45:16 -0800 X-Auth-Received: from [128.208.5.99] (nilakantha.cs.washington.edu [128.208.5.99]) (authenticated authid=youshi10) by smtp.washington.edu (8.13.7+UW06.06/8.13.7+UW06.09) with ESMTP id kBAKjGnU005597 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sun, 10 Dec 2006 12:45:16 -0800 Message-ID: <457C71DB.3000706@u.washington.edu> Date: Sun, 10 Dec 2006 12:45:15 -0800 From: Garrett Cooper User-Agent: Thunderbird 1.5.0.8 (Windows/20061025) MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <200612100905.30430.kirk@strauser.com> <20061210155022.GA28750@owl.midgard.homeip.net> <457C4156.8010309@computer.org> <17788.21019.357739.300962@jerusalem.litteratus.org> In-Reply-To: <17788.21019.357739.300962@jerusalem.litteratus.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-PMX-Version: 5.2.2.285561, Antispam-Engine: 2.5.0.283055, Antispam-Data: 2006.12.10.122933 X-Uwash-Spam: Gauge=IIIIIII, Probability=7%, Report='__CT 0, __CTE 0, __CT_TEXT_PLAIN 0, __HAS_MSGID 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __SANE_MSGID 0, __USER_AGENT 0' Subject: Re: Advantages of trimmed kernel? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Dec 2006 20:45:27 -0000 Robert Huff wrote: > Eric Schuele writes: > > >> FWIW... Its my understanding that >> - the memory saved would be negligible. >> > > How are we defining "negligible"? I know I've seen a pruned > kernel 25% smaller than GENERIC for the same release; I /think/ I've > seen one 33% smaller. Is that difference important? DammifIkno. > IF you're feeling paranoid, compile and install both. > (Assuming I'm correct in believing they install clean to separate > directories.) > > > Robert Huff > (running a custom kernel since 2.mumble) > As others have mentioned, the pluses to running a kernel without many of the trimmings is the fact that it does take less memory and less time to boot up / probe. Although this really isn't much of an issue with newer machines, due to the amount of available RAM in the machine (typically 512MB~1GB+), this does make a difference for some embedded systems and "limited resource architectures" (Pentium Pro, Pentium 2, etc), where RAM is a more of a luxury than on general purpose computers / servers. One thing that I will note though, is that compile time is also a factor for having a smaller kernel. I can recompile my kernel faster when I do source upgrades than I could with a generic kernel and all of the modules ("NO_MODULES = *" in make.conf). However, doing this has bit me in the arse a few times, so ultimately I recommend compiling / removing whatever you need with caution. My advice: heed what Lane said, but you can also trim down your kernel intelligently. You can save memory and disk space, as well as reduce recompile time in the long run by having a properly trimmed kernel. -Garrett