On Tue, Feb 11, 2014 at 07:32:46PM +0100, Stefan Priebe wrote: > Am 11.02.2014 17:22, schrieb Peter Lieven: > > > > > >>Am 11.02.2014 um 16:44 schrieb Stefan Hajnoczi <stefa...@gmail.com>: > >> > >>On Tue, Feb 11, 2014 at 3:54 PM, Stefan Priebe - Profihost AG > >><s.pri...@profihost.ag> wrote: > >>>in the past (Qemu 1.5) a migration failed if there was not enogh memory > >>>on the target host available directly at the beginning. > >>> > >>>Now with Qemu 1.7 i've seen succeeded migrations but the kernel OOM > >>>memory killer killing qemu processes. So the migration seems to takes > >>>place without having anough memory on the target machine? > >> > >>How much memory is the guest configured with? How much memory does > >>the host have? > >> > >>I wonder if there are zero pages that can be migrated almost "for > >>free" and the destination host doesn't touch. When they are touched > >>for the first time after migration handover, they need to be allocated > >>on the destination host. This can lead to OOM if you overcommitted > >>memory. > >> > >>Can you reproduce the OOM reliably? It should be possible to debug it > >>and figure out whether it's just bad luck or a true regression. > >> > >>Stefan > > > >Kernel Version would also be interesting as well as thp and ksm settings. > > Kernel Host: 3.10.26 > > What's thp / ksm? how to get those settings?
Transparent Huge Pages # cat /sys/kernel/mm/transparent_hugepage/enabled Kernel Samepage Merging # cat /sys/kernel/mm/ksm/run Stefan
