Subject: Re: Xen2/NetBSD 3.1 DomU running slowly
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Stephen Borrill <netbsd@precedence.co.uk>
List: port-xen
Date: 07/03/2007 15:15:09
On Sun, 3 Jun 2007, Manuel Bouyer wrote:
> 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

On the DOM0 presumably? Would doubling it be a fair increase?

-- 
Stephen