From owner-freebsd-geom@FreeBSD.ORG Fri Apr 23 13:50:57 2010 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6D113106566C; Fri, 23 Apr 2010 13:50:57 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 433BC8FC0C; Fri, 23 Apr 2010 13:50:57 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 0300F46B03; Fri, 23 Apr 2010 09:50:57 -0400 (EDT) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPA id 1C1418A025; Fri, 23 Apr 2010 09:50:53 -0400 (EDT) From: John Baldwin To: freebsd-current@freebsd.org Date: Fri, 23 Apr 2010 09:50:33 -0400 User-Agent: KMail/1.12.1 (FreeBSD/7.3-CBSD-20100217; KDE/4.3.1; amd64; ; ) References: <4BD06BD9.6030401@FreeBSD.org> In-Reply-To: <4BD06BD9.6030401@FreeBSD.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="koi8-r" Content-Transfer-Encoding: 7bit Message-Id: <201004230950.33999.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Fri, 23 Apr 2010 09:50:53 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=4.2 tests=AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: Alexander Motin , freebsd-geom@freebsd.org Subject: Re: Switchover to CAM ATA? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Apr 2010 13:50:57 -0000 On Thursday 22 April 2010 11:31:37 am Alexander Motin wrote: > If ataraid(4) should be reimplemented in GEOM, then how exactly? One > more separate RAID infrastructure in GEOM (third?) looks excessive. > Reuse gmirror, gstripe,... code would be nice, but will make them more > complicated and could be not easy for RAID0+1 (due to common metadata) > and RAID5 (due to lack of module in a base system). Scott's view (which sounds good to me) is that GEOM should include a library of routines for working with common transforms such as RAID1, striping, etc. Each ATA RAID vendor format would then consist of a small GEOM module that used the library routines to manage all the I/O and the bulk of the module would be managing a specific metadata format. -- John Baldwin