From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick Caulfield Subject: Re: [linux-lvm] enclosure separation/turnoff Message-ID: <20030212090412.GL1829@tykepenguin.com> References: <20030211175123.A5038@pdb-pc-6.rutgers.edu> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <20030211175123.A5038@pdb-pc-6.rutgers.edu> 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: Date: Wed Feb 12 03:04:01 2003 List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com On Tue, Feb 11, 2003 at 05:51:23PM -0500, Alexy Khrabrov wrote: > > I would like to see what would be a good way to use LVM > with a bunch of external SCSI enclosures ("boxes"). I have > several of these, with the number of drives ranging > from 1 to 2 to 4 per each. First I created a logical volume > per each box, but then realized the sizes were not exactly > matched, and now I get thrashing when trying to move stuff > from one enclosure box to another. So the first question > is, (1) how does one create a logical volume exactly corresponding > to an external box (a set of drives)? (2) Is it a good idea > to stripe an external box, given that data moves occur primarily > between the boxes, not within each? Then I'd stripe each > box with the number of stripes being the number of drives in it. > (3) Is there a way to resize the logical volumes so they are > remapped to their enclosures exactly, without reloading the > contents? (4) To make sure my latest box is done right, I created > a new volume group for it. Is this a good use for multiple > volume groups (other than the usual lone "system")? > > Now, I wanted to temporarily turn off the external enclosures > as I didn't need their contents. However, Linux would not boot > properly! Even when I disable the boxes in /etc/fstab, > it fails to boot; even when I deactivate the logical volumes > corresponding to the boxes with lvchange -a n > for each, and deactivate the last box with vgchange -a n , > failure on boot -- can't find many standard paths! Looks > like vgscan thinks something is still there and I get a message > "spinning sdd", while sdd is in one of the deactivated LVs, > and I'm forced to power on all of the boxes even while none > is mounted nor used. (5) How do I achieve clean separation so > that I can shut down any or all external enclosures easily? It sounds like you really just want to use each disk with a single partition on it. LVM in this instance is not going to buy you anything. -- patrick