CentOS - Sep 2009 - Install CentOS on Partition(!)-images as a Xen-guest

Hi!

Some weeks ago the "Running Xen"-book was recommended to me on this
list. A nice book, but it gave me crazy idea: One of the
recommendations (which sounds very reasonable to me) was to have
instead of a single file that serves as a disk-image to have to
files: one of them (which is mounted to hda1) serves as a partition
that holds the data, the other one (which mounts to hda2) is the swap
partition. The text in the books (admittedly it's a bit vague there)
lead me to the conclusion that to the Xen-machine they will look like
two partitions of a single drive hda. The advantage should be that it
is much easier to extend the data partition (Take the machine
offline. Extend the image with dd. Extend the filesystem on the image)

I created the two files as described in book. "Formatted" them with
mkswap and mkfs.ext3 (as described in the book) and added them to the
configuration file for the host. Now when I start the installation of
the host machine right in the beginning I get a message "/dev/hda1 has
a loop partition layout. To use this disk for the installation of
CentOS it must be initialized". When I don't allow formatting I get
caught in a loop ("Is a loop partition. Initialize?"), when I allow
formatting I get a partition on each of the devices (hda11 and hda21)
and I would be allowed to go on with the installation, but IMHO this
would defeat the purpose of the exercise

So my question:
 - is there some error in thinking on my side?
 - is this a situation that the installer can't deal with? (in other
   words: would it work if I copied a complete installation into the root
   partition-image and then booted that?)
 - or is there a reason that using partition images is not very
   popular (Googling around did not reveal anything useful)
 
Bernhard
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 188 bytes
Desc: not available
URL:
<http://lists.centos.org/pipermail/centos/attachments/20090915/f7db9618/attachment.sig>

On Tue, Sep 15, 2009 at 1:23 PM, Bernhard Gschaider <
bgschaid_lists at ice-sf.at> wrote:
>
> Hi!
>
> Some weeks ago the "Running Xen"-book was recommended to me on
this
> list. A nice book, but it gave me crazy idea: One of the
> recommendations (which sounds very reasonable to me) was to have
> instead of a single file that serves as a disk-image to have to
> files: one of them (which is mounted to hda1) serves as a partition
> that holds the data, the other one (which mounts to hda2) is the swap
> partition. The text in the books (admittedly it's a bit vague there)
> lead me to the conclusion that to the Xen-machine they will look like
> two partitions of a single drive hda. The advantage should be that it
> is much easier to extend the data partition (Take the machine
> offline. Extend the image with dd. Extend the filesystem on the image)
>
> I created the two files as described in book. "Formatted" them
with
> mkswap and mkfs.ext3 (as described in the book) and added them to the
> configuration file for the host. Now when I start the installation of
> the host machine right in the beginning I get a message "/dev/hda1 has
> a loop partition layout. To use this disk for the installation of
> CentOS it must be initialized". When I don't allow formatting I
get
> caught in a loop ("Is a loop partition. Initialize?"), when I
allow
> formatting I get a partition on each of the devices (hda11 and hda21)
> and I would be allowed to go on with the installation, but IMHO this
> would defeat the purpose of the exercise
>
> So my question:
>  - is there some error in thinking on my side?
>  - is this a situation that the installer can't deal with? (in other
>   words: would it work if I copied a complete installation into the root
>   partition-image and then booted that?)
>  - or is there a reason that using partition images is not very
>   popular (Googling around did not reveal anything useful)
>
> Bernhard
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>
>
Bernhard,

I'm actually probably the one that recommended the book to you.  I hope your
enjoying it so far.

As for your issue, I forwarded this to a friend of mine that is one of the
authors of the book.  He's interested in trying to fully understand what
you're trying to achieve.  He is wondering if you would mind sending an
email to contact at runningxen.com with your issue and the specific page(s)
that you are referencing.  He also wanted me to make you aware of the
Running Xen readers mailing list, which you can find more information about
at http://runningxen.com/ .  You can also find several other resources for
the book on the site as well.

Feel free to keep me in the loop as well.  I might have some advice to offer
once I fully understand everything.

Matt

--
Mathew S. McCarrell
Clarkson University '10

mccarrms at gmail.com
mccarrms at clarkson.edu
1-518-314-9214
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.centos.org/pipermail/centos/attachments/20090915/723eb661/attachment.html>