Enabling backports required for openmediavault-kvm plugin install?

On my recently installed OMV6 System I get following Error Message when I try to install openmediavault-kvm.

Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; export LANGUAGE=; export DEBIAN_FRONTEND=noninteractive; apt-get --yes --allow-downgrades --allow-change-held-packages --fix-missing --allow-unauthenticated --reinstall install openmediavault-kvm 2>&1' with exit code '100': Reading package lists...

Building dependency tree...

Reading state information...

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 openmediavault-kvm : Depends: qemu-system-ppc but it is not installable
E: Unable to correct problems, you have held broken packages.

OMV\ExecException: Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; export LANGUAGE=; export DEBIAN_FRONTEND=noninteractive; apt-get --yes --allow-downgrades --allow-change-held-packages --fix-missing --allow-unauthenticated --reinstall install openmediavault-kvm 2>&1' with exit code '100': Reading package lists...

Building dependency tree...

Reading state information...

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 openmediavault-kvm : Depends: qemu-system-ppc but it is not installable
E: Unable to correct problems, you have held broken packages. in /usr/share/openmediavault/engined/rpc/pluginmgmt.inc:247
Stack trace:
#0 /usr/share/php/openmediavault/rpc/serviceabstract.inc(619): Engined\Rpc\PluginMgmt->Engined\Rpc\{closure}('/tmp/bgstatusl5...', '/tmp/bgoutputrK...')
#1 /usr/share/openmediavault/engined/rpc/pluginmgmt.inc(251): OMV\Rpc\ServiceAbstract->execBgProc(Object(Closure))
#2 [internal function]: Engined\Rpc\PluginMgmt->install(Array, Array)
#3 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
#4 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('install', Array, Array)
#5 /usr/sbin/omv-engined(537): OMV\Rpc\Rpc::call('Plugin', 'install', Array, Array, 1)
#6 {main}

A quick search on the forum revealed several threads, where ryecoaaron advised people to fix their (in some cases previously messed up) systems by enabling backports. And indeed that fixed the issue for all of them. The thing is, my System is in a nearly virgin state. Yesterday installed on a new ssd from omv6 iso, just omv-extras, openmediavault-nut and openmediavault-compose added, no users nor data drives yet, no weird experiments like nvidia graphics drivers ...

And I'm pretty sure I had openmediavault-kvm installed on my previous OMV6 installation on the same machine without having backports activated.

ryecoaaron Are enabled backports a pre requirement for openmediavault-kvm now? If so, this should be mentioned somewhere in the documentation.

I have to say that I'm not so at all comfortable with enabling backports system-wide. So I didn't try it yet. Feels a bit like a solution that could break anytime (kvm or other system components).

I remember some sleepless nights years ago recovering a system screwed up by me having lighthearted enabled backports before.

edit: If (some) backported packages are needed for installing kvm now, is there a way to automate that install process so that it doesn't require enabling backports system-wide?

edit2: I'd still prefer a solution without backports at all, but if this is not possible ...

Quote from chente

An annotation about this has been added to the wiki.

https://wiki.omv-extras.org/do…_plugins:kvm#installation

Thank you (and ryecoaaron ) so much for contributing so much code, helpful documentation and time to this wonderful piece of software. This is acknowledged far too rarely.

Quote from ryecoaaron

As chente said, backports isn't always required but currently is because of how Debian changes things. But enabling backports is not really enabling it system wide. It only pins select packages. So, you don't have to worry about your entire system being taken over by backports. And as for something that could break anytime, I run the kvm plugin on my primary server (about 20 VMs) and probably use kvm more than 99.9% of OMV users. I would be the first to see breakage and have not seen that.

I have backports enabled on every system I have. Your one time mishap is not something that happens very often. There is nothing I can do to allow kvm installation without backports with the current state of the Debian repos. There are the only packages that are pinned from backport - https://github.com/OpenMediaVa…usr/sbin/omv-aptclean#L88 Only two are needed for the kvm plugin. Backports should not be needed with OMV 7.

Thanks for this Github link! This is what I needed. Now that I know this, I feel like the backports button in the gui needs more explanation right there! When I screwed up my system in the past, it wasn't omv and I'm still not experienced in handling backports and pinning. The only spot in the documentation of omv AND omv-extras, where backports are mentioned (aside from chente s new annotation), is this warning here for installing software manually. And also Debian documentation reminds you repeatedly to be very careful regarding backports.

My expectation with all these warnings in mind has been, that "enabling backports" in the gui indeed opens the flood gates for any backported debian stuff out there.

Anyway, enabled it, installed openmediavault-kvm and all went fine.

If use of backports is so essential for some omv-extras plugins and at the same time the expected impact to the system so limited by pinning just so few plugin specific packages, would enabling it as default be an option? (again with explanation, why)

The user doesn't expect to run into such error messages when installing a plugin.