From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Patterson Subject: Re: [PATCH 0/6] detect online disk resize Date: Fri, 05 Sep 2008 09:15:10 -0600 Message-ID: <1220627710.7790.17.camel@grinch> References: <20080904202714.10456.88061.stgit@bob.kio> <20080905082110.GN13941@edu.joroinen.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from g4t0017.houston.hp.com ([15.201.24.20]:33100 "EHLO g4t0017.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753571AbYIEPPO (ORCPT ); Fri, 5 Sep 2008 11:15:14 -0400 In-Reply-To: <20080905082110.GN13941@edu.joroinen.fi> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Pasi =?ISO-8859-1?Q?K=E4rkk=E4inen?= Cc: linux-scsi@vger.kernel.org, James.Bottomley@HansenPartnership.com, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, axboe@kernel.dk, andmike@linux.vnet.ibm.com, mike.miller@hp.com, genanr@emsphone.com, jmoyer@redhat.com On Fri, 2008-09-05 at 11:21 +0300, Pasi K=C3=A4rkk=C3=A4inen wrote: > > 1. For SCSI devices do: > >=20 > > # echo 1 > /sys/class/scsi_device//device/rescan > >=20 > > or > >=20 > > # blockdev --rereadpt > >=20 > > 2. Other devices (not device mapper) > >=20 > > # blockdev --rereadpt > >=20 > > I have tested this patch on SCSI and SmartArray (cciss) > > devices. Device mapper still does not recognize device size changes > > until the device is restarted. > >=20 >=20 > Hello and thanks for the patch!=20 >=20 > How about device mapper.. what's needed to make it detect/support onl= ine resizes? > I'm specificly interested in online resizing (growing) dm-multipath d= evices..=20 >=20 Yes, it would be nice if this patchset worked here too. It currently does not.=20 > Basicly I'd like to have LVM PV on dm-multipath device.. so first I n= eed to > get the actual disks resized, then dm-multipath device, and finally r= un pvresize. >=20 I did some testing with multipath here. I could get it working by shutting down the devices, resizing all the underlying paths using the above methods, restarting the devices, then running pvresize. This method does not help much given that most users cannot realistically shutdown a device. This patch series works fine with standard LVM/dm, i.e., resize using one of the above methods, then run pvresize. I was planning on looking into dm-multipath in the near future. Mike Anderson has done some work in this area in the past. > I know dm-multipath part can be done atm using this (hacky) method: > https://www.redhat.com/archives/dm-devel/2008-August/msg00033.html >=20 This is indeed ugly. It looks like they are pulling the paths out of the device, resizing them, and then adding them back in. > -- Pasi -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html