From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 5 Aug 2001 09:58:11 +0200 From: Luca Berra Subject: Re: [linux-lvm] LVM with multi-path disks? Message-ID: <20010805095811.A4626@colombina.comedia.it> References: <3B6B30C4.B4427F3D@cup.hp.com> <20010804174049.B564@colombina.comedia.it> <20010805022800.A26419@vestdata.no> <20010805091201.A4490@colombina.comedia.it> <20010805003257.A2728@glines.org> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <20010805003257.A2728@glines.org>; from mark@glines.org on Sun, Aug 05, 2001 at 12:32:57AM -0700 Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com On Sun, Aug 05, 2001 at 12:32:57AM -0700, Mark Glines wrote: > On Sun, Aug 05, 2001 at 09:12:01AM +0200, Luca Berra wrote: > > there is an (*horrible*) piece of code in pv_read_all_pv.c > > that deals with multiple entries for the same PV, so all duplicate > > PV are skipped, so the md will be the obly one detected. > > what probably happened to John is, that his PV was killed by > > this routine (they were duplicate and not md devices) > > I would only think this is a problem when md isn't being used. In the > above described situation, vgscan would see 2 devices which have md > headers (and ignore them), and one LVM signature (and use it)? Correct! > If the code does what you say, and LVM was using the dual-path SCSI > device directly, then it would detect one and ignore the other, and it > would still work as if there was only one route to the drive. this is also correct, i was just guessing there might be another dragon in this code, but we would need an output of vgscan -d from John to check. > However, in this case, md is in the middle, and its md's job to handle > multi-path. LVM should be ignoring md's lowlevel volumes anyway, and > act solely on the virtual device md exports. Am I missing something? John is not using md yet, you are correct in all you say. Regards, L. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \