On 09/13/2010 09:40 AM, Austin Godber wrote:
> So, were my instructions for creating HVM based images inaccurate? I
> had thought that HVM and the cluster compute type posed two separate
> issues. HVM works, but cluster compute images don't do to lack of
> support (for something) in the kernel.
>
I could be wrong but I believe the instructions you have are for
PVM-based images where you assign the image's AKI/ARI to a pv_grub
kernel/ramdisk. That pvm-grub kernel will then load your kernel from the
EBS root device using your EBS root device's /boot/grub/menu.lst.
The Cluster Compute works similarly, however, if you look at the Cent OS
HVM Cluster Compute reference image you'll see that it doesn't have an
AKI/ARI at all. I believe the HVM image instead loads Grub from the EBS
volume (rather then using the pv_grub AKI/ARI) and then uses stock Grub
to launch the kernel.
Also HVM kernels need high-performance pv drivers[0] in order to use
ephemeral stores and attached EBS vols[1]. Unfortunately when I applied
the patches, compiled, and tested the pv modules against a 2.6.32 kernel
I still couldn't get the resulting kernel to load (no console output
even!). I couldn't just use the 2.6.18 kernel from the reference image
(although I tried) since Ubuntu *has* to have a recent kernel otherwise
there are issues. So, I gave up on this for now until I have more time
to figure out what's needed to get a 2.6.32 kernel to launch on Cluster
Compute HVM machines.
In short, I think your instructions are for PVM and are identical to the
HVM process except that there's no AKI/ARI to assign and the kernel you
use with Cluster Compute HVM needs to be configured with the proper pv
modules from the Xen post[0].
Also, the EC2 dev docs state that user-provided/PVM kernel AMIs will not
work with the new Cluster Compute instance type:
[1]"Cluster compute instances require the use of HVM-based, Amazon
EBS-backed AMIs. Paravirtual (PV) AMIs employed by Linux instances or
other EC2 instance types that use paravirtual machine (PVM)-based
virtualization are not supported. Cluster compute instances do not
require the use of Amazon Kernel Images (AKIs) or Amazon RAMdisk Images
(ARIs) that are part of PVM-based AMIs used with other EC2 instance types."
HTH,
~Justin
[0]
http://lists.xensource.com/archives/html/xen-devel/2010-04/msg01361.html
[1]
http://docs.amazonwebservices.com/AWSEC2/latest/DeveloperGuide/index.html?concepts_cluster_compute.html
Received on Mon Sep 13 2010 - 11:56:22 EDT