qubesdb-daemon: FATAL: vchan initialization failed

[Jasper Tron]

Hello everyone.

I'm trying to create a TemplateVM for NixOS. I have xenstore working
in a NixOS HVM, and I installed qubes-core-qubesdb (and qubes-libvchan-xen),
but I'm having trouble starting qubesdb-daemon. It fails with:

  > FATAL: vchan initialization failed

Does anyone have any ideas or suspicions about what might be causing this
or how I could go about debugging it?

Thanks,
Jasper

[Marek Marczykowski-Górecki]

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Make sure that dom0 instance is running. Also you need to have
xen-evtchn and xen-privcmd modules loaded.

- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
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[Marek Marczykowski-Górecki]

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On Fri, Aug 26, 2016 at 06:06:56PM -0500, Jasper Tron wrote:

> On Thu, Aug 4, 2016 at 2:06 AM, Marek Marczykowski-Górecki
> <marm...@invisiblethingslab.com> wrote:
> > Make sure that dom0 instance is running. Also you need to have
> > xen-evtchn and xen-privcmd modules loaded.
>

> Dom0 instance of qubesdb-daemon is running (from when I started the HVM).
> The xen_privcmd module is loaded in both hvm and dom0.
> Running `modprobe xen_evtchn` loads the module in hvm but not dom0.
> But I still get the same error.
> Fedora AppVMs (where qubesdb-daemon is working) don't have xen_evtchn either;
> is that module only required for HVMs or something?

In our kernel it is built-in by default, not a separate module. Also
check if you have xen-gnttab module loaded.

Try starting qubesdb-daemon through strace - you'll probably see some
error related to opening some device file, it should shed some light on
the problem.

- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
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