Xen users - May 2009 - Questions Converting from ESXi to Xen

I currently have a dual processor (2x quad core xeons) with 16gb ram and a
few hard disks.

Being plagued with horrible performance of virtual machines (only running 2
vm''s utilizing about 2gb ram usage and very very little processing). I
just
can''t stand the fact that a single core machine with 1gb of ram will
outperform my current setup i have on esxi. It takes about 15 seconds to
load a static web page on any VM I create. So I can only assume its very
poor disk performance, a horrible virtual network switch, or the hypervisor
is just slow in telling the vm to use any of the 99% of free resources. (or
all of the above).

So I''ve made the decision to buy another server and install Xen -
converting
the current VM''s over. (I should have just went with Xen in the first
place
I think).

Anyways, I can''t seem to find any articles or pages that relate to
converting an ESXi VM to Xen. (All that I find is how to convert Xen to
ESXi) - Which is a bit mind boggling because ESXi in my opinion is just
horrible!

If anyone could help me find the information I''m looking for in
converting a
VM to Xen, that would be great.

And I would assume and hope to hear that disk i/o, resource allocation from
hardware to vps, as well as installing distros from an image is at least
several times faster.

Thanks for any help/advice and perhaps some comfort in knowing that I wont
be wasting time/money converting from esxi to xen.


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>I currently have a dual processor (2x quad core xeons) with 16gb ram and a
few hard disks.
>
>Being plagued with horrible performance of virtual machines (only running 2
vm''s utilizing about 2gb ram usage and very very little processing). I
just can''t stand the fact >that a single core machine with 1gb of
ram will outperform my current setup i have on esxi. It takes about 15 seconds
to load a static web page on any VM I create. So I can >only assume its very
poor disk performance, a horrible virtual network switch, or the hypervisor is
just slow in telling the vm to use any of the 99% of free resources. (or >all
of the above).
>
>So I''ve made the decision to buy another server and install Xen -
converting the current VM''s over. (I should have just went with Xen in
the first place I think).
>
>Anyways, I can''t seem to find any articles or pages that relate to
converting an ESXi VM to Xen. (All that I find is how to convert Xen to ESXi) -
Which is a bit mind >boggling because ESXi in my opinion is just horrible!
>
>If anyone could help me find the information I''m looking for in
converting a VM to Xen, that would be great.
It''s fairly easy either way and depends on what Guest OS. For windows,
all versions
of windows always load IDE drivers into the critical device database and are
ready
at boot. Just image out of esx and into whatever block device you are backing
your
vm''s with. ''qemu-img convert'' for example if using
files... dd or a more intelligent
app like ghost works as well.

If Linux, you need to change the kernel back to a non xen kernel and create a
initrd
that has ide drivers for that kernel, then image out and in like above.

Either way, remove the vmware tools prior to imaging out.

FWIW, *you* have a mis-configuration in your ESXi setup, I have plenty
Win/Linux/Solaris
vm''s that run everything from database to web/fileservers on ESXi and
it runs very well.

jlc

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On Fri, May 22, 2009 at 5:11 AM, Joseph L. Casale
<JCasale@activenetwerx.com> wrote:
>>If anyone could help me find the information I''m looking for in
converting a VM to Xen, that would be great.
>
> It''s fairly easy either way and depends on what Guest OS. For
windows, all versions
> of windows always load IDE drivers into the critical device database and
are ready
> at boot.
Really? Recently I tried to migrate a native eeepc Windows
installation into virtualbox, thinking that since they both use IDE
it''d just work. It didn''t. This article helped :
http://www.virtualbox.org/wiki/Migrate_Windows

Same thing should apply to migrating Windows from anything to Xen.

-- 
Fajar

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>Really? Recently I tried to migrate a native eeepc Windows
>installation into virtualbox, thinking that since they both use IDE
>it''d just work. It didn''t. This article helped :
>http://www.virtualbox.org/wiki/Migrate_Windows
>
>Same thing should apply to migrating Windows from anything to Xen.
I forgot about the HAL, the last few I did were Windows 2008 which
only has one, but the HAL can be manipulated in other versions of
windows by booting the vm off a winpe iso and copying the correct
HAL while renaming it if required.

As far as the part about "hard disc support" the author is incorrect
in his assumption. So long as the mass storage controller *is* in the
critical device database, it will boot (depending on which versions of
windows, an edit to boot.ini may be required). It doesn''t memorize,
like
linux, it will only boot with what it currently has support for unless
you add more drivers.

If you look at the linked batch file, it simply adds additional drivers
into the registry.

What finally made your eeepc migration work?

jlc

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On Fri, May 22, 2009 at 9:54 AM, Joseph L. Casale
<JCasale@activenetwerx.com> wrote:
> As far as the part about "hard disc support" the author is
incorrect
> in his assumption. So long as the mass storage controller *is* in the
> critical device database, it will boot (depending on which versions of
> windows, an edit to boot.ini may be required). It doesn''t
memorize, like
> linux, it will only boot with what it currently has support for unless
> you add more drivers.
>
> If you look at the linked batch file, it simply adds additional drivers
> into the registry.
>
> What finally made your eeepc migration work?
The linked batch file :)

Enabling IOAPIC is not enough (it simply shows black boot screen, no
progress whatsoever).
Changing the HAL (using /HAL=xxx in boot.ini) gives blue screen.
running the BAT file before exporting (together wit IOAPIC) made it
work. This is also consistent with information on MS knowledge base
http://support.microsoft.com/kb/314082

-- 
Fajar

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