From owner-freebsd-current@FreeBSD.ORG Mon Oct 10 02:51:37 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5EB89106568D; Mon, 10 Oct 2011 02:51:37 +0000 (UTC) (envelope-from perryh@pluto.rain.com) Received: from agora.rdrop.com (agora.rdrop.com [IPv6:2607:f678:1010::34]) by mx1.freebsd.org (Postfix) with ESMTP id 01EDB8FC0C; Mon, 10 Oct 2011 02:51:36 +0000 (UTC) Received: from agora.rdrop.com (66@localhost [127.0.0.1]) by agora.rdrop.com (8.13.1/8.12.7) with ESMTP id p9A2pYow054158 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Sun, 9 Oct 2011 19:51:35 -0700 (PDT) (envelope-from perryh@pluto.rain.com) Received: (from uucp@localhost) by agora.rdrop.com (8.13.1/8.12.9/Submit) with UUCP id p9A2pYEk054157; Sun, 9 Oct 2011 19:51:34 -0700 (PDT) Received: from fbsd81 ([192.168.200.81]) by pluto.rain.com (4.1/SMI-4.1-pluto-M2060407) id AA09602; Sun, 9 Oct 11 19:05:28 PDT Date: Mon, 10 Oct 2011 02:04:34 -0700 From: perryh@pluto.rain.com To: jwd@freebsd.org Message-Id: <4e92b522.f71Y8d/d4QhvelRN%perryh@pluto.rain.com> References: <344794801.20111005101957@serebryakov.spb.ru> <4E8C1426.60107@quip.cz> <251861322.20111005125825@serebryakov.spb.ru> <4E8C6E85.90005@quip.cz> <4E8CD662.90202@quip.cz> <4E8DA627.60003@quip.cz> <711721489.20111006175611@serebryakov.spb.ru> <4E919DFF.8090607@quip.cz> <20111010012631.GA45500@FreeBSD.org> In-Reply-To: <20111010012631.GA45500@FreeBSD.org> User-Agent: nail 11.25 7/29/05 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Mon, 10 Oct 2011 16:21:00 +0000 Cc: 000.fbsd@quip.cz, lev@freebsd.org, ivoras@freebsd.org, freebsd-current@freebsd.org, freebsd-geom@freebsd.org Subject: Re: RFC: Project geom-events X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Oct 2011 02:51:37 -0000 John wrote: > > ... gpart should show warning message if user is trying to put > > GPT on non real disk devices. ... > This also seem to prevent something useful like: > > # camcontrol inquiry da0 > pass2: Fixed Direct Access SCSI-5 device > pass2: Serial Number 3TB1BKGX00009036W9EN > pass2: 600.000MB/s transfers, Command Queueing Enabled > # camcontrol inquiry da25 > pass27: Fixed Direct Access SCSI-5 device > pass27: Serial Number 3TB1BKGX00009036W9EN > pass27: 600.000MB/s transfers, Command Queueing Enabled > > # gmultipath label ZFS0 da0 da25 > # gpart create -s gpt $device > # gpart add -s 128 -t freebsd-boot $device # Create 64K boot partition > # gpart add -s 4m -t freebsd-ufs -l mb$dev $device # small partition > # gpart add -t freebsd-zfs -l $dev $device # Remaining space for zfs > > It seems like protecting your partitions with multiple > paths would be a good thing. I've been experimenting with > this and end up with corrupt partitions. The setting of $device is not shown, but I suppose it is the name of the multipath provider. I'm not familiar with gmultipath, but it would not surprise me if (like most GEOMs) it were putting its metadata in the last block(s) of its providers and therefore encountering the same issues as gmirror and glabel. In that case, the best fix may be to define the multipathing per-partition instead of per-device (if that is possible), or to use MBR/BSD instead of GPT for partitioning.