[StarCluster] [Starcluster] Version of StartCluster with support for Amazon Cluster Compute Images

[Justin Riley]

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