From owner-freebsd-current@FreeBSD.ORG Wed Oct 5 09:29:51 2011 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9076D106566B; Wed, 5 Oct 2011 09:29:51 +0000 (UTC) (envelope-from lev@FreeBSD.org) Received: from onlyone.friendlyhosting.spb.ru (onlyone.friendlyhosting.spb.ru [IPv6:2a01:4f8:131:60a2::2]) by mx1.freebsd.org (Postfix) with ESMTP id 532188FC18; Wed, 5 Oct 2011 09:29:51 +0000 (UTC) Received: from lion.home.serebryakov.spb.ru (unknown [IPv6:2001:470:923f:1:b9fd:2f11:cd06:1a6]) (Authenticated sender: lev@serebryakov.spb.ru) by onlyone.friendlyhosting.spb.ru (Postfix) with ESMTPA id 063054AC2D; Wed, 5 Oct 2011 13:29:49 +0400 (MSD) Date: Wed, 5 Oct 2011 13:29:41 +0400 From: Lev Serebryakov Organization: FreeBSD Project X-Priority: 3 (Normal) Message-ID: <1453791516.20111005132941@serebryakov.spb.ru> To: Alexander Motin In-Reply-To: <4E8C20EA.5060501@FreeBSD.org> References: <1927112464.20111004220507@serebryakov.spb.ru> <4E8B7A27.5070908@quip.cz> <344794801.20111005101957@serebryakov.spb.ru> <4E8C1426.60107@quip.cz> <251861322.20111005125825@serebryakov.spb.ru> <4E8C20EA.5060501@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1251 Content-Transfer-Encoding: quoted-printable Cc: freebsd-geom@FreeBSD.org, Miroslav Lachman <000.fbsd@quip.cz>, current@freebsd.org Subject: Re: RFC: Project geom-events X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: lev@FreeBSD.org List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Oct 2011 09:29:51 -0000 Hello, Alexander. You wrote 5 =EE=EA=F2=FF=E1=F0=FF 2011 =E3., 13:18:34: > geom_raid addresses this problem in own way. As soon as RAID BIOSes > expect RAIDs to be built on raw physical devices and probe order is not > discussed, geom_raid exclusively opens underlying providers immediately > after detecting supported metadata. So even if volume is broken or But it could be not first, who taste component of mirror, am I right? If geom_part will be first, will it "take away" component from geom_raid? Or it could not? If it works in any case (exclusive open spoils geom_part), it could be used in all other classes without any metadata infrastructure, but it seems, that geom_mirror, for example, could pickup metadtata from last parition instead of raw device... I'm not sure here. But, in any case, maybe standard first 16 bytes of metadata in pure-GEOM classes and filter in GEOM infrastructure itself ("not pass provider for tasting to anything but class, written in first 16 bytes of last sector") looks good idea, IMHO. --=20 // Black Lion AKA Lev Serebryakov