libvirt users - Nov 2018 - Re: How to change the default connection of 'virsh' tool from 'qemu' to 'xen' ?

On Wed, Oct 31, 2018 at 09:32:30AM +0100, Andrea Bolognani
wrote:
>On Wed, 2018-10-31 at 10:56 +0900, Minjun Hong wrote:
>> Hi.
>>
>> Thanks to help of this mailing list (especially Jim Fehlig), I have
finished setup of libvirt.
>> However, there is something weird. It is that I installed libvirt on 5
servers but
>> the default connection of one of them is 'qemu:///' even if
those of the others are all 'xen:///'.
>
>You probably installed the QEMU driver on that one server only: if
>that's indeed the case, the easiest way to fix the inconsistency
>would be to uninstall it.
>
>If that fails...
>
>> I searched how to change it but, I only found a bypass adding "
LIBVIRT_DEFAULT_URI='xen:///' " in my .bashrc file.
>> Currently, value of the variable (LIBVIRT_DEFAULT_URI) is set to
'qemu:///'.
>> Since the bypass makes the virtualization type of the server visible
'qemu' to the open stack, I have to change libvirt configuration.
>>
>> I also checked some configure files under '/etc/libvirt', such
as libvirt.conf, libvirtd.conf and libxl.conf.
>> But I have no idea, how and what to change.
>> Please give me some advise. It will be a big help for me.
>
>... you can simply set
>
>  uri_default = "xen:///"
>
>in /etc/libvirt/libvirt.conf to change the system-wide default URI
>without having to mess with environment variables.
>
Or in .config/libvirt/libvirt.conf for a non-root user.
>--
>Andrea Bolognani / Red Hat / Virtualization
>
>_______________________________________________
>libvirt-users mailing list
>libvirt-users@redhat.com
>https://www.redhat.com/mailman/listinfo/libvirt-users

On Wed, Oct 31, 2018 at 05:33:09PM +0100, Martin Kletzander
wrote:
> On Wed, Oct 31, 2018 at 09:32:30AM +0100, Andrea Bolognani wrote:
> > On Wed, 2018-10-31 at 10:56 +0900, Minjun Hong wrote:
> > > Hi.
> > >
> > > Thanks to help of this mailing list (especially Jim Fehlig), I
have finished setup of libvirt.
> > > However, there is something weird. It is that I installed libvirt
on 5 servers but
> > > the default connection of one of them is 'qemu:///' even
if those of the others are all 'xen:///'.
> >
> > You probably installed the QEMU driver on that one server only: if
> > that's indeed the case, the easiest way to fix the inconsistency
> > would be to uninstall it.
> >
> > If that fails...
> >
> > > I searched how to change it but, I only found a bypass adding
" LIBVIRT_DEFAULT_URI='xen:///' " in my .bashrc file.
> > > Currently, value of the variable (LIBVIRT_DEFAULT_URI) is set to
'qemu:///'.
> > > Since the bypass makes the virtualization type of the server
visible 'qemu' to the open stack, I have to change libvirt
configuration.
> > >
> > > I also checked some configure files under '/etc/libvirt',
such as libvirt.conf, libvirtd.conf and libxl.conf.
> > > But I have no idea, how and what to change.
> > > Please give me some advise. It will be a big help for me.
> >
> > ... you can simply set
> >
> >  uri_default = "xen:///"
> >
> > in /etc/libvirt/libvirt.conf to change the system-wide default URI
> > without having to mess with environment variables.
> >
>
> Or in .config/libvirt/libvirt.conf for a non-root user.
Alternatively, you can set the following env variable in your .bashrc to the
desired URI:

LIBVIRT_DEFAULT_URI

Erik

On Thu, 2018-11-01 at 16:40 +0100, Erik Skultety wrote:
> On Wed, Oct 31, 2018 at 05:33:09PM +0100, Martin Kletzander wrote:
> > On Wed, Oct 31, 2018 at 09:32:30AM +0100, Andrea Bolognani wrote:
> > > On Wed, 2018-10-31 at 10:56 +0900, Minjun Hong wrote:
> > > > I searched how to change it but, I only found a bypass
adding " LIBVIRT_DEFAULT_URI='xen:///' " in my .bashrc file.
> > > > Currently, value of the variable (LIBVIRT_DEFAULT_URI) is
set to 'qemu:///'.
> > > > Since the bypass makes the virtualization type of the server
visible 'qemu' to the open stack, I have to change libvirt
configuration.
> > > > 
> > > > I also checked some configure files under
'/etc/libvirt', such as libvirt.conf, libvirtd.conf and libxl.conf.
> > > > But I have no idea, how and what to change.
> > > > Please give me some advise. It will be a big help for me.
> > > 
> > > ... you can simply set
> > > 
> > >  uri_default = "xen:///"
> > > 
> > > in /etc/libvirt/libvirt.conf to change the system-wide default
URI
> > > without having to mess with environment variables.
> > 
> > Or in .config/libvirt/libvirt.conf for a non-root user.
> 
> Alternatively, you can set the following env variable in your .bashrc to
the
> desired URI:
> 
> LIBVIRT_DEFAULT_URI
... Which, as you can see above, is exactly what OP is already doing
and what they're looking for an alternative to ;)

Also note that, at least as far as I understand, they want to make
sure the xen:/// default URI is picked up by an high-level management
application (in this case OpenStack), which suggests the new default
should be set globally rather than per-user, which is the reason why
I didn't mention the approach Martin suggested.

I still believe the best solution is to just uninstall the QEMU
driver so that everything will work as expected without having to
mess with configuration files at all.

Let's wait for OP to try either approach out and report back :)

-- 
Andrea Bolognani / Red Hat / Virtualization