From owner-freebsd-geom@FreeBSD.ORG Tue Apr 27 14:00:15 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 DEE991065672; Tue, 27 Apr 2010 14:00:15 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-ew0-f224.google.com (mail-ew0-f224.google.com [209.85.219.224]) by mx1.freebsd.org (Postfix) with ESMTP id DB02B8FC1D; Tue, 27 Apr 2010 14:00:11 +0000 (UTC) Received: by ewy24 with SMTP id 24so3985066ewy.33 for ; Tue, 27 Apr 2010 07:00:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=6HEfOoOq1/j2SHU/Txa/LgniEPqJi+ozw7civoJuLB4=; b=mGdQpsi/C3CR8J6gfeXpoPQUHT48iVywUbbpPyajcVUMTf4SxydM5ta0DjDWqlMwy/ lF80vebL4OJhR/KYDOCK8nY101BsMuz/JSbLGoINFvIT08LZ7MYVLsJc17Yuq6XbCcb1 Xd/CkjS5gvFZGi/uahhqjbTQ0RrA2l873wZt8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=ICyjSST0gEYGsRTz11r3iv6dnpEr12ZB3FVnpxbo6Pt/U3L7dqk5PPP6skrM0a7gId mQAZwKqUCXnoDMb/Nf2Ss4u9tCdDp9s3Rm9uhfB+Ej4LvbemGrw+b6IZRigjDKkxzh+S QzYfMNGgkcS2jqFSFnJ3yfwaVJX+VsAQ1X3bI= Received: by 10.103.133.7 with SMTP id k7mr3196523mun.128.1272376805450; Tue, 27 Apr 2010 07:00:05 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id j10sm22240921mue.48.2010.04.27.07.00.04 (version=SSLv3 cipher=RC4-MD5); Tue, 27 Apr 2010 07:00:04 -0700 (PDT) Sender: Alexander Motin Message-ID: <4BD6EDD6.8010403@FreeBSD.org> Date: Tue, 27 Apr 2010 16:59:50 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.24 (X11/20100402) MIME-Version: 1.0 To: =?UTF-8?B?RGFnLUVybGluZyBTbcO4cmdyYXY=?= References: <4BD06BD9.6030401@FreeBSD.org> <4BD099E6.6000402@FreeBSD.org> <4BD0A689.8000508@thekeelecentre.com> <4BD0ACD2.3040805@FreeBSD.org> <86och53tpl.fsf@ds4.des.no> In-Reply-To: <86och53tpl.fsf@ds4.des.no> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Maxim Sobolev , FreeBSD-Current , Richard Tector , 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: Tue, 27 Apr 2010 14:00:16 -0000 Dag-Erling Smørgrav wrote: > Maxim Sobolev writes: >> Richard Tector writes: >>> Could I also add that the removal of ataraid would affect those >>> users who dual-boot with Windows and rely on the psuedo-raid >>> provided by most Intel chipsets to be able to share the same pair of >>> disks. >> Well, this won't be a problem if we have GEOM classes that can >> understand metadata created by the ATA RAID BIOS(es). > > Most pseudo-raid kit has nifty features like checksum offloading, > composite writes etc. which can improve performance considerably. You > can't access those from GEOM. Have you ever seen them documented? Does the need to specifically handle dozens of incompatible implementations with limited resources worth those (probably not major) benefits? -- Alexander Motin