I have HIGHMEM enabled on my kernel but I have to limit the memory to ~6GB for snapshots to work. I added mem=6000M to my kernel command line and snapshots work fine. I also found this thread on the LKML that has a patch that may fix the problem: http://marc.theaimsgroup.com/?l=linux-kernel&m=104549874128521&w=2 The only machine we have that has >4GB RAM is a production box and I really don't want to test something in production (call me crazy :) ). Here are my specs: Kernel 2.4.18-27.SHRbigmem LVM 1.0.7 Hope this helps, Andy. On Fri, 2003-05-16 at 08:38, Lauro, John wrote: > > > 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. > > Can you give more specifics/examples/web links/etc? Does this mean I > should avoid LVM completely with HIGHMEM? What if any other problems > should I expect with LVM (and/or other software)? > > > > 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. > > Is this easy to reproduce? If so, how? Sounds like I am either a > lucky early adopter of a >4GB Libux system, and/or the problem is rare > even on HIGHMEM systems? > > Thanks. > > > _______________________________________________ > linux-lvm mailing list > linux-lvm@sistina.com > http://lists.sistina.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ -- Andrew Rechenberg <arechenberg@shermfin.com> Infrastrucutre Team, Sherman Financial Group _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
