From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 15 Jun 2001 16:51:35 +0200 From: "Heinz J. Mauelshagen" Subject: Re: [linux-lvm] expanding physical disks Message-ID: <20010615165135.A4266@sistina.com> References: <20010612212804.P1658@pc.ilinx> <200106130710.f5D7AhaX005430@webber.adilger.int> <20010613152032.A18554@colombina.comedia.it> <20010615161151.B9980@hal.mailgate.net> Mime-Version: 1.0 In-Reply-To: <20010615161151.B9980@hal.mailgate.net>; from hal@mailgate.net on Fri, Jun 15, 2001 at 04:11:51PM +0200 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 Fri, Jun 15, 2001 at 04:11:51PM +0200, Hugo Lombard wrote: > On Wed, Jun 13, 2001 at 03:20:32PM +0200, Luca Berra wrote: > > On Wed, Jun 13, 2001 at 01:10:42AM -0600, Andreas Dilger wrote: > > > Brian Murrell writes: > > > > How does LVM deal with physical disks that can get bigger or smaller, > > > > such as a hardware RAID device? What happens to a PV on a hardware > > > > RAID-5 device that is presented to the system as a single (say scsci) > > > > target when you put a few more disks in it and tell the hardware raid > > > > device to add them to the given (scsi) target that a PV was created > > > > on? (what a mouthful). > > > > > > Doesn't work at this time. LVM will only see what was originally there > > > at the time pvcreate was run (or possibly vgcreate/vgextend). > > At the moment your only chance is to create partitions on it and use those > > partitions as PVs > > > > Just a thought, a bit off topic perhaps. ;-) > > If you're using LVM primarily as a way to make it possible for you to > expand your storage space on-line (and on-mount-point) wouldn't it be > "easier" to _just_ use the RAID? i.e. expand the RAID volume on the > controller, so basically the "disk" is bigger now, and the just "grow" > your partition, extend your filesystem, and that's it? I think you're right in case you can live with the restrictions involved. If the amount of resizable volumes a single smart controller can support is enough, you can surely go with that solution. When it comes to more storage you need a logical volume manager to group multiple disk subsystems together in order to support large storage configurations. > > It's a thought I've been toying with since seeing the IBM ServeRAID's > capability to grow volumes. I've not attempted any testing though, so > this is pure speculation... > > (PS: All this means nothing if you're using LVM for it's other > features, like striping, but then the RAID can do that too...) Plus LVM's features to move data around online in order to relocate it to faster/bigger/newer disk subsystems, to have more that just a couple of resizable devices, support for hardware block device reconfiguration without any changes in the namespace of the logical volumes, snapshot support etc. Regards, Heinz -- The LVM Guy -- > > > > > -- > "You show me an American who can keep his mouth shut and I'll eat him." > -- Newspaperman from Frank Capra's _Meet_John_Doe_ > --------------------------------------------------------------------------- > Hugo Lombard Infoline (Pty) Ltd > System Administrator > --------------------------------------------------------------------------- > _______________________________________________ > 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 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Heinz Mauelshagen Sistina Software Inc. Senior Consultant/Developer Am Sonnenhang 11 56242 Marienrachdorf Germany Mauelshagen@Sistina.com +49 2626 141200 FAX 924446 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-