Subject: Re: Xen2/NetBSD 3.1 DomU running slowly
To: Stephen Borrill <netbsd@precedence.co.uk>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: port-xen
Date: 06/03/2007 19:02:36
On Thu, May 31, 2007 at 09:24:51AM +0100, Stephen Borrill wrote:
> Every now and then I get reports of a customer's DomU running slowly and, 
> sure enough, when I connect it takes ages to login. However, it's running 
> at 100% idle and the other DomU on the same box is fine. A reboot of the 
> DomU fixes it. When it happened today, I saw the following on the Dom0 
> console (which is running quickly and responsively):
> 
> xen_shm_map: ENOMEM
> xen_shm_map: ENOMEM1
> xvif3.0: can't map packet page
> 
> The first two are debugging, I believe, but the third looks suspicious...
> 
> The kernels are 3.1_STABLE from 20th Nov 2006. Have there been pullups 
> that fix this, i.e. should I be updating? I'm not in a position to upgrade 
> to NetBSD 4.0/Xen3 at the moment.

You may have an usage that requires more VM space for inter-domains 
communications than is currenly allocated. You can try increasing XENSHM_NPAGES
in sys/arch/xen/i386/xen_shm_machdep.c

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--