[libvirt-users] configuring a lxc guest to run 32bits from a 64bits host under libvirt-lxc

[Thierry Parmentelat]

Hi again

Sorry for the late reaction on this..

So everything seems to work fine for me when using the setting below, except maybe for one little point

I was kind of expecting that 
# virsh -c lxc:/// lxc-enter-namespace my_32bits_vm ...
would run in a 32bits environment too, but from what I can see it is not the case

I take it it can be argued, reading the documentation for lxc-enter-namespace again, that might well be the intended behaviour

In this case I would argue it would make a lot of sense to have either :
(a) lxc-enter-namespace to do the right thing personality-wise as well (possibly through an option if there are legacy concerns)
or (b) a virsh function/command that can help retrieve the right personality
like e.g.
virsh -c lxc:/// personality the_vm
that would return either linux32 or linux64 so it would be possible to run
$(virsh -c lxc:/// personality the_vm) virsh -c lxc:/// lxc-enter-namespace the_vm — /usr/bin/env yum groupinstall ...

Or is there something else available already that I am missing altogether ?

Thanks — Thierry


On 02 Jul 2014, at 11:29, Daniel P. Berrange <berrange at redhat.com> wrote:

> On Wed, Jul 02, 2014 at 12:56:18AM +0200, Thierry Parmentelat wrote:
>> Hi again
>> 
>> Answering my own e-mail on a few points:
>> 
>> . first off, stupid me, http://libvirt.org/format.html indeed is empty and it seems to be by design, but the subtrees are not, like e.g.
>> http://libvirt.org/formatdomain.html
>> 
>> . from this page it seems like using something like
>>  <os>
>>    <type arch='i686'>exe</type>
>>    <init>/sbin/init</init>
>>  </os>
>> in the guest XML config should do the trick
> 
> Yes, setting arch='i686' should force the container to have a 32-bit
> personality on x64_64. Likewise for ppc vs ppc64, s390 vs s390x, etc
> 
> Regards,
> Daniel
> -- 
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