From owner-freebsd-hackers@FreeBSD.ORG Sun Aug 21 04:53:36 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EEC7016A41F; Sun, 21 Aug 2005 04:53:36 +0000 (GMT) (envelope-from anderson@centtech.com) Received: from mh2.centtech.com (moat3.centtech.com [207.200.51.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8EE6B43D48; Sun, 21 Aug 2005 04:53:36 +0000 (GMT) (envelope-from anderson@centtech.com) Received: from [192.168.42.23] (andersonbox3.centtech.com [192.168.42.23]) by mh2.centtech.com (8.13.1/8.13.1) with ESMTP id j7L4rYns080124; Sat, 20 Aug 2005 23:53:34 -0500 (CDT) (envelope-from anderson@centtech.com) Message-ID: <430808DF.1000405@centtech.com> Date: Sat, 20 Aug 2005 23:53:51 -0500 From: Eric Anderson User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.10) Gecko/20050815 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Don Lewis References: <200508210444.j7L4ihEg028916@gw.catspoiler.org> In-Reply-To: <200508210444.j7L4ihEg028916@gw.catspoiler.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, hselasky@c2i.net Subject: Re: Parking disk drive heads X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Aug 2005 04:53:37 -0000 Don Lewis wrote: > On 20 Aug, Eric Anderson wrote: > > >>As a data point, I've been using 64mb compact flash cards (rated at 100k >>writes) in about 100 Soekris boxes (running FreeBSD) for about 4 years, >>and they are all still working, except for one. Now, most compact flash >>cards are rated at 1 million writes. >> >>And yes, I'm logging to the card and everything.. > > > I've been using a laptop drive in my firewall and mail relay box for > noise and power consumption reasons. The drive specs only give an > expected lifetime of a few years when running 24x7, and I just had to > replace a drive that had been in service about four years. I've given > some thought to using flash, but I'm concerned about the number of > writes, especially since a mail relay (maybe 1K messages/day) is going > to be somewhat write intensive. What would be nice is a flash-backed md > device that would flush its contents to flash on power fail. If you are running 6.0 or 7.0-CURRENT, you should check out gjournal recently released from a SoC project. It can do some of this. Maybe another possible solution would be a memory backed md device unioned over a flash device? Anyhow, a cheap solution would be 2 flash devices mirrored with gmirror. By the time it burns up, you'll be able to swap it with the same size for half the price, and if you put them on different IDE channels or use usb, you can do it live. Eric -- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology Anything that works is better than anything that doesn't. ------------------------------------------------------------------------