Subject: Re: XEN 3 DomU loses network and dies
To: None <port-xen@NetBSD.org>
From: Damian Lubosch <dl@xiqit.de>
List: port-xen
Date: 01/23/2008 08:39:11
Manuel Bouyer schrieb:
>
>
> There's no balloon driver at all in NetBSD. All memory allocations to
> domains are static.
> But, the hypervisor is then unable to reclaim memory if it evers gets low.
> How much free memory does xm info (or xm top) reports, and how many
> virtual disk and network interfaces to you have in dom0 ?
>
>   
Hi Manuel!

Because of the balloon driver I wondered because the amount of used
memory (in xm top) varies a little bit around the maximum.
When I set up the system  (dom0 + 5 domUs) xm info / top reported about
50 MB free RAM for the hypervisor, and after the problems began I
switched off one domU to get about 108 MB of free RAM but the problems
still persists.

I recompiled the dom0 kernel to having 64 vnd devices and the default of
xbd devices. In my /dev I generated 16 of both.

The problem still occured yesterday. But most of the times I was able to
login via the console over the dom0 to the problem making domU, then I
had to "shutdown -r now" and on the next boot it stopped after telling
(I think it was) "unknown type console at xenbus0 id 0 not configured"
(I'll post the error message when it happens again). I had to go then to
the dom0 xm shutdown the domU and to recreate it again.

Could it be an error of the domU?

Thank you!

Damian


PS:
xm info tells:
host                   : pless
release                : 4.0
version                : NetBSD 4.0 (XEN3_DOM0) #0: Thu Dec 27 19:11:33
CET 2007  root@pless:/xen/usr/src/sys/arch/i386/compile/XEN3_DOM0
machine                : i386
nr_cpus                : 1
nr_nodes               : 1
sockets_per_node       : 1
cores_per_socket       : 1
threads_per_core       : 1
cpu_mhz                : 2199
hw_caps                :
078bfbff:e3d3fbff:00000000:00000010:00000001:00000001:00000001
total_memory           : 1022
free_memory            : 108
xen_major              : 3
xen_minor              : 1
xen_extra              : .2
xen_caps               : xen-3.0-x86_32
xen_scheduler          : credit
xen_pagesize           : 4096
platform_params        : virt_start=0xfc000000
xen_changeset          : unavailable
cc_compiler            : gcc version 4.1.2 20061021 prerelease (NetBSD
nb3 20061125)
cc_compile_by          : root
cc_compile_domain      :
cc_compile_date        : Thu Dec 27 19:09:12 CET 2007
xend_config_format     : 4