Re: NetBSD/xen with 4 GB RAM

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Jan 24, 2008 at 03:16:14PM +0200, Martti Kuparinen wrote:
> Hi,
> 
> How is NetBSD dom0 supposed to work on hosts with 4 GB or more memory?
> 
> I installed NetBSD/i386 4.0_STABLE on Dell PowerEdge 850 (it was previously
> running NetBSD/i386 3.1.1 as dom0) and configured it as dom0. I'm having
> problems with this dom0, domUs simply will not start as they die during the
> early stages of startup.
> 
> # xm list
> Name                                        ID   Mem VCPUs      State   
> Time(s)
> Domain-0                                     0   256     1     r-----     
> 16.8
> 
> # cat /usr/pkg/etc/xen/xxx
> kernel = "/usr/pkg/etc/xen/kernels/NetBSD-XEN3_DOMU.gz"
> disk = [ 'file:/xen/netbsd-4GB.tmpl,0x1,w' ]
> memory = 512
> name = "xxx"
> vif = [ 'mac=00:16:3e:11:11:11, bridge=bridge0' ]
> 
> # xm create xxx
> Using config file "/usr/pkg/etc/xen/xxx".
> Started domain xxx
> 
> # xm list
> Name                                        ID   Mem VCPUs      State   
> Time(s)
> Domain-0                                     0   256     1     r-----     
> 19.3
> 
> In the logs I found these:
> 
> [2008-01-24 14:19:23 106] WARNING (XendDomainInfo:1154) Domain has crashed: 
> name=xxx id=7.
> [2008-01-24 14:19:23 106] ERROR (XendDomainInfo:1284) VM xxx restarting too 
> fast (1.098851 seconds since the last restart).  Refusing to restart to 
> avoid loops.
> 
> Next I found the solution in our other Xen 3 server, i.e. I modified
> /grub/menu.lst to limit the memory to 3072MB. I tried different values
> here and the largest working value is somewhere between 3340M and 3350M.

This is an issue I've seen on some Dell servers too (Dell 2950 in my case).
I suspect it's an issue between the hypervisor and segments reported by the
BIOS. My workaround was also to restrict the memory on the Xen command line.

I have other systems running a 32bit Xen with 4GB or RAM (they're
supermicro servers, also intel-based), and I've no trouble at all.

-- 
Manuel Bouyer, LIP6, Universite Paris VI.           
Manuel.Bouyer%lip6.fr@localhost
     NetBSD: 26 ans d'experience feront toujours la difference
--