From owner-freebsd-questions@FreeBSD.ORG Mon Dec 20 22:25:43 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CBFBD16A4CE for ; Mon, 20 Dec 2004 22:25:43 +0000 (GMT) Received: from smtpout.mac.com (smtpout.mac.com [17.250.248.46]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8D56F43D45 for ; Mon, 20 Dec 2004 22:25:43 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from mac.com (smtpin07-en2 [10.13.10.152]) by smtpout.mac.com (8.12.6/MantshX 2.0) with ESMTP id iBKMPhIU019721; Mon, 20 Dec 2004 14:25:43 -0800 (PST) Received: from [10.1.1.245] (nfw1.codefab.com [199.103.21.225]) (authenticated bits=0) by mac.com (Xserve/smtpin07/MantshX 4.0) with ESMTP id iBKMPfDE010287; Mon, 20 Dec 2004 14:25:42 -0800 (PST) In-Reply-To: <6.2.0.14.2.20041220135549.05fdaa88@localhost> References: <6.2.0.14.2.20041220135549.05fdaa88@localhost> Mime-Version: 1.0 (Apple Message framework v619) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <137C9E12-52D6-11D9-9340-003065ABFD92@mac.com> Content-Transfer-Encoding: 7bit From: Charles Swiger Date: Mon, 20 Dec 2004 17:25:38 -0500 To: Brett Glass X-Mailer: Apple Mail (2.619) cc: questions@freebsd.org Subject: Re: ECC status in FreeBSD X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Dec 2004 22:25:43 -0000 On Dec 20, 2004, at 3:55 PM, Brett Glass wrote: > I'm getting ready to build some (hopefully) high reliability servers > with > ECC memory. I'd like to put FreeBSD on them. What facilities (if any) > does > FreeBSD have for: > > 1) Reporting the status of ECC memory (errors corrected, errors > uncorrected, etc.)? > 2) Responding to uncorrectable errors? A quick check of the archives suggests a FreeBSD version of a kernel module which pays attention to the ECC status of various chipsets is available from: http://docs.freebsd.org/cgi/getmsg.cgi?fetch=113348+0+archive/2001/ freebsd-hackers/20010318.freebsd-hackers ...based on the work for Linux at: http://www.anime.net/~goemon/linux-ecc/ > 3) Mapping out portions of memory that produce repeated errors? You can set an option in the loader to limit the physical memory available to FreeBSD, which could serve the purpose. However, your RAM isn't a hard drive, so the ad-sector remapping used by hard drives is not fully applicable. Your machine is expected not to have any part of memory fail reproducably, but if you do, it's time to use the warranty and replace the entire chip. > It seems to me that, for an operating system that prides itself on > server > stability and performance, such features are a must. ECC is a fine idea, but the motherboard chipset pretty much does everything that is required (except for the reporting/syslogging), so the kernel doesn't need to be specially involved for the system to benefit from ECC protection. -- -Chuck