From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <3B6D85EB.4AFF6D2D@cup.hp.com> Date: Sun, 05 Aug 2001 10:44:11 -0700 From: John DeFranco MIME-Version: 1.0 Subject: Re: [linux-lvm] LVM with multi-path disks? References: <3B6B30C4.B4427F3D@cup.hp.com> <20010804174049.B564@colombina.comedia.it> <20010805022800.A26419@vestdata.no> <20010805091201.A4490@colombina.comedia.it> <20010805003257.A2728@glines.org> <20010805095811.A4626@colombina.comedia.it> Content-Transfer-Encoding: 7bit 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" To: linux-lvm@sistina.com Hi, So thanks for the replys so far. From some of the replys I was not completely clear on what my issue. I'll just cover everything in detail so avoid any misunderstanding. I have a fc connected hw raid box. I have three luns defined in the raid box. It is connected to the host by an Emulex controller and is using the emulex lpfcdd light pulse driver. The raid box has two connections to the host. So I see three luns on scsi2 and three on scsi3 (as I would expect): Host: scsi2 Channel: 00 Id: 111 Lun: 00 Vendor: HP Model: A6188A Rev: HP01 Type: Direct-Access ANSI SCSI revision: 03 Host: scsi2 Channel: 00 Id: 111 Lun: 01 Vendor: HP Model: A6188A Rev: HP01 Type: Direct-Access ANSI SCSI revision: 03 Host: scsi2 Channel: 00 Id: 111 Lun: 02 Vendor: HP Model: A6188A Rev: HP01 Type: Direct-Access ANSI SCSI revision: 03 Host: scsi3 Channel: 00 Id: 109 Lun: 00 Vendor: HP Model: A6188A Rev: HP01 Type: Direct-Access ANSI SCSI revision: 03 Host: scsi3 Channel: 00 Id: 109 Lun: 01 Vendor: HP Model: A6188A Rev: HP01 Type: Direct-Access ANSI SCSI revision: 03 Host: scsi3 Channel: 00 Id: 109 Lun: 02 Vendor: HP Model: A6188A Rev: HP01 Type: Direct-Access ANSI SCSI revision: 03 [root@jack scsi]# This is a list of the device mapping: bus 2 lpfc CLAIMED channel 2.0 CLAIMED Id=? target 2.0.111 tgt CLAIMED disk 2.0.111.0 sd CLAIMED HP A6188A /dev/sdc /dev/sg3 disk 2.0.111.1 sd CLAIMED HP A6188A /dev/sdd /dev/sg4 disk 2.0.111.2 sd CLAIMED HP A6188A /dev/sde /dev/sg5 bus 3 lpfc CLAIMED channel 3.0 CLAIMED Id=? target 3.0.109 tgt CLAIMED disk 3.0.109.0 sd CLAIMED HP A6188A /dev/sdf /dev/sg6 disk 3.0.109.1 sd CLAIMED HP A6188A /dev/sdg /dev/sg7 disk 3.0.109.2 sd CLAIMED HP A6188A /dev/sdh /dev/sg8 bus 1 sym53c8xx CLAIMED [root@jack /root]# Disk /dev/sdc (/dev/sdf) is partitioned and part of a vg. As things are now vgscan will not find the vg. I can create one and it ok while the system is booted, but as soon as I reboot I cannot see the vg anymore. I have attached a vgscan -d output. I'm not certain exactly how I would use md in this context, and I'm not sure that I really want to since I'm using hw raid. Thanks! Luca Berra wrote: > > 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 > / \ > _______________________________________________ > linux-lvm mailing list > linux-lvm@sistina.com > http://lists.sistina.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html -- ========== Cheers -jdf