From owner-freebsd-scsi@FreeBSD.ORG Fri May 9 06:17:38 2014 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 01D23E80 for ; Fri, 9 May 2014 06:17:38 +0000 (UTC) Received: from post.cs.huji.ac.il (post.cs.huji.ac.il [132.65.116.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A9AEBB4A for ; Fri, 9 May 2014 06:17:37 +0000 (UTC) Received: from th-04.cs.huji.ac.il ([132.65.80.125]) by post.cs.huji.ac.il with esmtp id 1Wie7i-000IXt-J7; Fri, 09 May 2014 09:17:34 +0300 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.2 \(1874\)) Subject: Re: 'Wiring down' iSCSI devices / stop swapping dev nodes... From: Daniel Braniss In-Reply-To: <88E7AF042B7C82964163CEAF@study64.tdx.co.uk> Date: Fri, 9 May 2014 09:17:33 +0300 Content-Transfer-Encoding: quoted-printable Message-Id: <620EE312-8B43-4E65-A534-6CAA92982CAD@cs.huji.ac.il> References: <963D4F6D5D95769A2C8A07D1@Mail-PC.tdx.co.uk> <88E7AF042B7C82964163CEAF@study64.tdx.co.uk> To: Karl Pielorz X-Mailer: Apple Mail (2.1874) Cc: freebsd-scsi@freebsd.org X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 May 2014 06:17:38 -0000 On May 8, 2014, at 9:32 PM, Karl Pielorz wrote: >=20 >=20 > --On 8 May 2014 17:12:24 +0300 Daniel Braniss = wrote: >=20 >> one solution is to use gpart (8) >> gpart create -s GPT /dev/dan >> =85 >> gpart add -t freebsd-ufs -l d0/p1 /dev/dan >>=20 >> and you can use now >> /dev/gpt/d0/p1 >>=20 >> which [should] be true whatever iscsi decides to call device. >=20 > I hadn't thought of that - mostly because the devices underlying the = iSCSI are already gparted (i.e. the iSCSI target is a GPT partition on = an underlying disk). >=20 > I'm just trying it now - looks like it will work (Ok, it's created - I = need to test failure etc.) >=20 > Is there any performance hit from having 'GPT within a GPT' kind of = thing going on? - I suppose I could just share out the raw disk (i.e. = /dev/daX) via iSCSI and then there'd be only one layer of partitioning = going on... I'm not sure if that's a good idea or not :) just from my guts, I don=92t think there is any noticeable overhead, = considering that TCP already adds allot, one more indirection is probably negligible. danny