virt-manager upgrade

[Andrea Bolognani]

On Fri, Oct 07, 2022 at 10:28:07AM +0100, Daniel P. Berrangé wrote:
> On Fri, Oct 07, 2022 at 10:21:18AM +0100, Richard W.M. Jones wrote:
> > On Thu, Oct 06, 2022 at 07:14:39PM +0000, woodcab wrote:
> > > Hello,
> > >
> > >  Still new to Linux and had a few questions regarding upgrading to 4.1.0
> > >
> > >  I'm using virt-manager 2.2.1 on Ubuntu MATE 20.4. There is an
> > > upgrade available for Ubuntu Mate to MATE 20.4.1. I am told that
> > > this is a minor upgrade and that it can be done with my files in
> > > place. I have backed up my files and VMs along with the .xml
> > > files. My question is how to best proceed with that upgrade? If
> > > virt-manager is upgraded to 4.1.0 in the process, will my VMs that
> > > were setup in 2.2.1 still work in 4.1.0? Or should I upgrade
> > > virt-manager to an intermediate version before going to 4.1.0?
> >
> > I don't think I've ever had to worry about existing VMs when upgrading
> > libvirt or virt-manager (BTW I think *libvirt* is more relevant to
> > this since that's what is actually managing the VMs).  I have upgraded
> > libvirt many times on my system that runs VMs even while the VMs were
> > running.
>
> Libvirt goes to quite alot of trouble to ensure you can upgrade
> the host software stack and not cause problems to your VMs. You
> can even upgrade libvirt itself, while QEMU VMs are running,
> and it should seemlessly reconnect.
>
> Upgrading virt-manger itself will not have any impact of VMs,
> since virt-manager is merely a GUI frontend.
>
> Downgrading software, however, is totally unsupported, and you
> get to keep any pieces & put it back together if it breaks :-)
>
> > Since you've done the right thing by backing up the existing VMs and
> > *.xml files, you should be good even in the unlikely case that
> > anything goes wrong during the upgrade, so I guess go for it!

I'll add that going from 20.04 to 20.04.1 is unlikely to bring in a
significantly different version of any package, so you can basically
ignore compatibility concerns in your scenario :)

-- 
Andrea Bolognani / Red Hat / Virtualization