From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Heinz J . Mauelshagen" Subject: Re: [linux-lvm] snapshot with bigmem broken Message-ID: <20030516125958.B24422@sistina.com> References: <37885B2630DF0C4CA95EFB47B30985FB020EBD2E@exchange-1.umflint.edu> Mime-Version: 1.0 In-Reply-To: <37885B2630DF0C4CA95EFB47B30985FB020EBD2E@exchange-1.umflint.edu>; from jlauro@umflint.edu on Wed, May 14, 2003 at 06:50:46AM -0400 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 May 16 06:08:02 2003 List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com On Wed, May 14, 2003 at 06:50:46AM -0400, Lauro, John wrote: > Hello, > > > > I did more testing, and it appears that snapshots in LVM will not work > with either 4GB or or 64GB support enabled in the kernel under 2.4.20. > This includes both LVM 1.0.7 or the latest LVM2. > That's a known issue. You are faced with a VM flaw. I presume that it's not LVM snapshots only bacause HIGHMEM is basically broken. > > > Is there anyone using LVM snapshots with 64GB RAM support (or even 4GB > RAM support, as snapshots would be good for at least our medium size > servers if not our large ones)? Is so, let me know the kernel version > and LVM version you are using so that I can try it. Probably not, because the system lifelocks on bounce buffers (which is the sympton of the principle HIGHMEM bug). Obviously not a lot of HIGHMEM users out there raising priorities to fix this. > > > > PS: As mentioned previously, everything else in LVM seems to be ok > with larger kernel memory models. It's mainly just snapshots that > appear to be broken using the latest LVMs and kernel. > > > -- 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 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-