Re: xen-bootable DomU images for linux

[Brad Spencer <brad%anduin.eldar.org@localhost>]

Brook Milligan <brook%nmsu.edu@localhost> writes:

[snip]

> I downloaded a Debian image and tried to create a Xen instance with the following conf file modeled after yours:
>
> kernel = "/usr/pkg/lib/xen/boot/hvmloader"
> builder='hvm'
> device_model_version="qemu-xen-traditional"
> memory = 2048
> cpu_weight = 64
> name = "debian"
> vif = [ 'mac=aa:00:00:d1:00:09,bridge=bridge0' ]
> disk = [ 'file:/path/to/xen/debian-live-11.6.0-amd64-cinnamon.iso,hda,w', ]
> boot='c'
> vfb = [ 'type=vnc,vnclisten=X.X.X.X' ]
>
> I get the following message:
>
> 	WARNING: you seem to be using "kernel" directive to override HVM guest firmware. Ignore that. Use "firmware_override" instead if you really want a non-default firmware

That is fine, it will still work.  My base Xen configs sometimes date
from Xen 3.x and have a bit of junk in them.

> Is this something to worry about?
>
> More importantly, I am not able to connect to the running instance.  Connecting with “xl console” just hangs.  Perhaps vnc should work, but I’m not sure how to do that.  I have tried vncviewer commands that are analogous to what I use for other systems, but nothing connects, despite trying several different IP addresses for the vfb.  Do I also need to define a display?
>
> I’m not sure how to see what is actually running.  Does anyone have a known-good image and conf file to share (off list).
>
> Any suggestions welcome.

I have never used "xl console" with a HVM, only vnc, but be aware that
the vnc server is only listening on 127.0.0.1 on the DOM0 (the vnclisten
seems to be ignored, for me anyway).  So, you have to have vncviewer on
the DOM0 itself and use X forwarding or use ssh and port forward
something like 127.0.0.1:5900 (or whatever port you ended up with) from
the DOM0 to an external address or other location.  With the instance
running, do a "netstat -an|grep 59" and see if there is anything running
on 5900+ .. that will be the vnc address+port you want to hit.

You *may* want to use "boot='d'" and specifiy that the iso is a CDROM.
Something like this:

'file:/lhome/xen/isos/archlinux-2022.08.05-x86_64.iso,ioemu:hdc:cdrom,r'

You will probably also want to add a hard drive as some of the
installers get unhappy without one (if I remember it all correctly).
Usually I put the hard drive on hda, and use hdc for the cdrom.

You will be fine NOT using qemu traditional with a file backstore (my
example had qemu traditional specified), but if you use LVM LVs, the
upstream qemu doesn't deal correctly with them (I posted about this on
port-xen a while ago).

As for trying the Debian distro, I don't remember trying that one.
Assuming that nothing is too strange about it, it will probably be fine.
It *MAY* (and probably will) notice that it is running in a Xen world
and try to be a PVHVM or even PVH guest after it starts which should not
be a problem.

> Thanks a lot.
>
> Cheers,
> Brook




-- 
Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - http://anduin.eldar.org