From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Anderson Subject: Re: Status of resizing/growing dm-multipath devices on the fly Date: Wed, 6 Aug 2008 12:36:02 -0700 Message-ID: <20080806193602.GA9941@linux.vnet.ibm.com> References: <20080806125355.GM3771@edu.joroinen.fi> <20080806143751.GO3771@edu.joroinen.fi> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20080806143751.GO3771@edu.joroinen.fi> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development Cc: Andrew Patterson List-Id: dm-devel.ids Pasi K?rkk?inen wrote: > On Wed, Aug 06, 2008 at 03:48:12PM +0200, Domenico Viggiani wrote: > > * Pasi K=E4rkk=E4inen wrote: > > >=20 > > > Is it possible to resize (grow) dm-multipath devices on the=20 > > > fly nowadays? > > >=20 > > > I googled and found some discussions about the subject, but=20 > > > the conclusion seemed to be it's not possible.. that was a=20 > > > while ago, so I was wondering if this has been fixed/implemented.. > > >=20 > > > Using LVM and adding another new LUN/PV is not an option=20 > > > always.. it's a lot easier to manage the whole thing if it's=20 > > > possible to resize/grow existing LUNs on the fly. > >=20 > > Nowadays all disk-arrays make online LUN extension a breeze but > > unfortunately it seems that dm-multipath is still not able to see new= size > > without downtime: > > http://www.redhat.com/archives/dm-devel/2007-August/msg00205.html > > Look also at this recent thread on RHEL5 mailing-list where you can f= ind > > also a post from a Red Hat representative: > > http://www.redhat.com/archives/rhelv5-list/2008-July/msg00267.html > >=20 > > Sure, you can just add a new LUN, pvcreate and vgextend but it is not= a > > viable solution because it causes LUN proliferation. > >=20 > > Sincerely, I'm still subscribed to this mailing-list only to see if s= omeone > > solve this SHAME! > > It's a feature that Linux really needs. > >=20 > > Hope someone pick this cry of pain! > >=20 >=20 > Thanks for the reply. >=20 > Does someone know what's the actual problem in this? meaning why it has= n't > been done yet..=20 It has to do with the block layer not using the new size value while ther= e are openers. Andrew submitted a patch series (url below) a while ago to try and addres= s this issue, but I do not know the status. I added Andrew to the cc. http://thread.gmane.org/gmane.linux.scsi/41623 -andmike -- Michael Anderson andmike@linux.vnet.ibm.com