Re: Creating a Guest from an ISO

Fajar A. Nugraha
Mon, 20 Feb 2012 06:00:10 -0000

On Mon, Feb 20, 2012 at 6:25 AM, Chris Spencer <chrisspen@gmail.com>
wrote:
> Hi,
>
> I''m new to Xen, and I just installed Xen 4.1 on 64-bit Ubuntu
Server
> 11.10. I''ve confirmed I''m booting into the Xen kernel.

Judging from the state of https://help.ubuntu.com/community/Xen ,
there''s not much interest (at least not from those who''s
willing to
edit the documentation) for Xen on Ubuntu.

I haven''t used the combination you use, so my replies will be generic
ones from someone who used Xen on other distro/version.

>
> Now I''m trying to create guests for 64-bit and 32-bit Ubuntu
Desktop
> 11.10. I''ve downloaded the ISOs, and while I''ve been
reading through
> the docs, several things are unclear to me.
>
> First, there seems to be two primary methods for creating guests. One,
> using `xen create ...` and another using `xen-create-image`. Which
> should I use?

There''s no such thing as "xen create". There''s
"xm create" (or "xl
create", but that''s another story). Read the wiki link above, some
of
it should still be valid, and it explains what xen-create-image and
"xm create" is for.


>
> Second, I don''t see any simple way to create a guest from an ISO.
I''ve
> searched for hours, but all I could find was one brief mention at
> http://wiki.debian.org/Xen, stating that Xen is unable to directly
> read ISO images, and that a workaround was to create a loop device,
> and use that device in a Xen cfg file to create the guest. Is this
> correct? I found some suggestions that the --mirror parameter could be
> used to specify the ISO filename, but I haven''t been able to get
this
> to work. Is that possible?

Last time I tried (which, admittedly was quite a while ago), the only
OS that was able to be installed as PV domU from ISO was
opensolaris/openindiana. For linux, you need to either:

- use ISO to install HVM guests, and then convert it to PV (pretty
complicated for newbies), OR
- use a special kernel and initrd to do network install, e.g.
http://archive.ubuntu.com/ubuntu/dists/oneiric/main/installer-i386/current/images/netboot/xen/
. Highly recommended if your internet connection is fast-enough, as
this is a well-supported method. OR
- create an image using other method (e.g. xen-create-image) which
does not involve the normal distro installer.

>  You appear to have a missing vif-script, or network-script, in the
>  Xen configuration file /etc/xen/xend-config.sxp.

That''s another different issue. Did you do what it tells you to do?

I''ve said this a lot lately: if you simply want something that just
works, Xenserver/XCP might be a better choice for servers, while
virtualbox might be a better choice if you use it on PC/notebook.

If you DO manage to get it to work correctly with Xen, you''ll have a
very flexible and powerful virtualization setup. Please spend some
time to edit the wiki.

--
Fajar