At Fri, 24 Oct 2025 11:03:40 -0700, Jeff Rizzo <riz%tastylime.net@localhost> wrote:
Subject: upgrading my dom0 box (again?) - foolish?
>
> So. Is there any hope for moving this to
> Xen 4.20 and a NetBSD 10.1 dom0, or should
> I just leave well enough alone and phase
> this system out entirely? (I certainly
> want to do that in the long run, but it
> feels like it could give me another couple
> years)
>
> If I were to do an upgrade, can someone
> suggest a good order of operations with
> fallback? Apologies for the vagueness of
> this - but clearly I've been out of Xen
> world for a while now. :)
I think I would jump direct to 10.1_STABLE and Xen 4.20.
It is more or less easy enough to test if you're willing to restore from
full backups. :-)
First make sure you can easily boot a old 9.2 GENERIC kernel in your
dom0 and run the system bare metal with everything not related to Xen
starting and running properly.
I've never used pygrup, but since your pygrub domUs just run XEN3_DOMU
kernels I think you should be able to just copy those kernels for those
domUs to the dom0 root and update their configs to load them directly at
domU creation time. I always put PV kernels right in the root directory
and then have a domU.conf line like:
kernel = "/netbsd-XEN3_DOMU"
You should do that conversion and get rid of pygrub and test everything
before doing any upgrades. It all should work fine without pygrub in
4.11 or even much older.
Then you should be ready to do the dom0 upgrade:
boot from new install media and do a sysinst upgrade, complete with
boot the new system with GENERIC and make sure the hardware all
works, etc. Make sure all the LVMs still look OK.
do the etcupdate dance (sysinst left behind /.sysinst for this):
etcupdate -s /.sysinst
reboot with GENERIC again and make sure everything looks right and
everything not related to Xen is running correctly.
build/install a 10.1_STABLE XEN3_DOM0 kernel.
You could try rebooting with the new XEN3_DOM0 kernel the old Xen-4.11
kernel and tools, and that should still work with a 10.x dom0.
If it all works then shutdown and reboot GENERIC again.
In any case do not try to change xentools while running Xen!!!!
Uninstall xenkernel411 and xentools411.
Upgrade all packages, hopefully as easy as "pkgin update && pkgin fug".
You might want to boot GENERIC again and check things, but that dance
may be getting boring by now, especially if your dom0 doesn't do
anything else but Xen.
Install the new xenkernel420 and xentools420, linking/copying the kernel
in place as necessary.
Now you should be able to reboot with the new Xen kernel and tools and
everything should start, domUs and all.
Note you shouldn't have to change any Xen-related configuration files if
you've been using the "new" syntax for everything. There is a small
chance 4.20's xl(1) might be a bit more picky about only allowing new
syntax, but the documentation still only calls it "deprecated". I've
never had a Xen system old enough to only support the old syntax so I've
never ever even used it.
I have worked on patches to Xen that should allow NetBSD (or even all of
the rc.d-using BSDs) to fully support the Xen "hotplug" system of
choosing which tools to use depending on which dom0 kernel has booted.
They're not quite done yet, and not fully tested, but they should allow
one to have multiple versions of Xen installed simultaneously and then
just boot whichever one you want (going forward, at least, or if
backported to previous Xen releases), but for now sadly none of that
works properly in the stock distributions.
--
Greg A. Woods <gwoods%acm.org@localhost>
Kelowna, BC +1 250 762-7675 RoboHack <woods%robohack.ca@localhost>
Planix, Inc. <woods%planix.com@localhost> Avoncote Farms <woods%avoncote.ca@localhost>
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