From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Heinz J . Mauelshagen" Subject: Re: [linux-lvm] Snapshot Problem JFS Message-ID: <20030620110908.A29306@sistina.com> References: <2E7F9C924F6A6546AF777BD072071EC6091243@mars.lbmc.net> Mime-Version: 1.0 In-Reply-To: <2E7F9C924F6A6546AF777BD072071EC6091243@mars.lbmc.net>; from dsornig@lbmc.com on Thu, Jun 19, 2003 at 09:07:30PM -0500 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: Fri Jun 20 04:23:01 2003 List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com On Thu, Jun 19, 2003 at 09:07:30PM -0500, David Sornig wrote: > I am running RedHat 9.0 > Kernel 2.4.20-8 > LVM Version 1.0.5+(22/07/2002) > > I have a 1.4T LogVol with 400G of space being used on a JFS file system. > > The LVM is working excellent. However, I cannot create a snapshot. I run the following lvcreate command as per the man page and get the following error: > > lvcreate --error "Cannot allocate memory" creating VGDA for "/dev/Volume00/snap01" in kernel > David, memory allocated to the snapshot needs free physical RAM. With 400GB and default snapshot extent size we're talking about ~1GB (using virtual memory for snapshot exception tables so that the table doesn't need to be in RAM completely any longer is a work item for LVM2). Do you really expect that much change to your 1.4TB LV during the lifetime of the snapshot ? If you use it for a backup, you might get along with a couple of GB allocated to the snapshot reducing exception table size drastically. > Not sure why this is happening. I have read the list and maybe I just don't understand the problem. These servers have 4 Gigs of RAM. > > Regards, > > David -- Regards, Heinz -- The LVM Guy -- *** Software bugs are stupid. Nevertheless it needs not so stupid people to solve them *** =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Heinz Mauelshagen Sistina Software Inc. Senior Consultant/Developer Am Sonnenhang 11 56242 Marienrachdorf Germany Mauelshagen@Sistina.com +49 2626 141200 FAX 924446 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-