Re: Suggestions for upgrading dom0

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Oct 17, 2018 at 09:28:32AM -0700, Jeff Rizzo wrote:
> Benign neglect has left me in a situation where I have a dom0 at a remote
> site which is in need of an upgrade, but being on-site for it is a lot of
> trouble, and I'm willing to take some risk of everything blowing up in order
> to do it remotely.  That said, I'd like to minimize my risk to the extent
> possible, and I was hoping to get some suggestions from others.
> 
> 
> The dom0 in question is running NetBSD 6.1.2/amd64, and Xen 4.1.6, and it's
> been up for 1062 days(!).  The domUs are mostly PV, with one HVM, all
> running versions of NetBSD from 5.1 to 7. (In fact, the thing that's getting
> me to finally bite the bullet is that I can't get a NetBSD 8 PV kernel to
> run).  The domUs are backed by LVM volumes.  Xen is installed via pkgsrc.
> 
> 
> What I'm *hoping* I can do is upgrade to NetBSD-8.0 and whatever the latest
> Xen in pkgsrc is (looks like 4.11.x maybe?) with something approximating
> this:
> 
> 
> First, my standard NetBSD upgrade:
> 
> - install new netbsd kernel and kernel modules in a new line of /boot.cfg ,
> shut down all domUs, and reboot. (Unclear whether I can get the xen4.1.6
> kernel working with the new dom0 kernel; I'll probably have to fiddle to get
> things booted with a xen 4.11.x kernel as well)

A netbsd8 dom0 kernel should boot with xen4.1.6. I'd also install
a /netbsd-GENERIC as backup, which can easily be booted from the
boot loader.

I hope you have remote console access ?

> [...]
> - whether xend from xen 4.11 is likely to give me trouble

there's no xend any more.

> 
> - whether I'll need to update any scripts.  I'm pretty sure the
> pkgsrc-provided xen scripts are stock (that is, I didn't patch them locally)

Yes, you have to remove the /etc/rc.d xen scripts and install
the new ones. I don't think you need to change /etc/rc.conf but I may
not remember properly.

> 
> - what I should be looking at that I haven't.
> 
> The last time I did anything fancy with a dom0 (specifically, getting this
> one set up) would have been just before NetBSD 6 was released, so anything
> that's changed in the Xen world since then is likely to surprise me.  I
> kind-of recall that xm has been replaced by xl, but I'm not yet sure of the
> ramifications of that.

You may need to ajust some guest's config, but nothing serious.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--