Oracle Database Huge Pages

Oracle DBAs will use Oracle Hug pages to increase Oracle database performance : http://docs.oracle.com/cd/E11882_01/server.112/e10839/appi_vlm.htm#UNXAR394

The only requirement for huge-pages (2MB pages) is that you run a HVM instance. However, all the Oracle AMIs are PVM.

For now to use huge pages with Oracle on EC2,  the best option would be to go with SUSE HVM AMI and then install the Oracle Database on the EC2 instance. 

HVM and PVM : Oracle AMIs

AWS AMIs are either Para Virtual Machine (PVM) or Hardware Virtual Machine (HVM) images. All of the AMIs from Oracle are currently only PVM-based. Therefore, they will not run on cluster compute or i2 instance types.

More information on HVM-based instances types:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using_cluster_computing.html#concepts_cluster_compute_hvmAMI
http://aws.amazon.com/ec2/faqs/#Does_use_of_Cluster_Compute_Instances_differ_from_other_Amazon_EC2_instance_types

Currently, the new i2 instance types are HVM only:
http://aws.amazon.com/about-aws/whats-new/2013/12/19/announcing-the-next-generation-of-amazon-ec2-high-i/o-instance/

More on HVM and PVM can be found here:
http://serverfault.com/questions/222010/difference-between-xen-pv-xen-kvm-and-hvm

If you are looking to run Oracle solutions on Oracle Enterprise Linux and require more then 68 GB of memory, you would have to run on hs1.8xlarge (117 GiB) as all other instance types with more then 68 GB are HVM. See more here: http://aws.amazon.com/amazon-linux-ami/instance-type-matrix/

Oracle OEL AMIs running on cluster compute instances

AWS cluster compute instances types (cc1.4xlarge,cg1.4xlarge, cr1.8xlarge, cc2.8xlarge), all require to be run as HVM instances.  Currently, all the AMIs from Oracle are PVM only. Windows EC2 instances can only be HVM as PV does not support windows, so Windows AMIs or HVM based Linux AMIs can be used.

OVM based Oracle AMIs can also not be run on cluster compute instance types.

Oracle Linux and HVM AMIs

OEL is not supported on cr1.8xlarge. These instances run as HVM-base instances.  All Oracle AMIs are PVM.    For HVM you have to go with Windows, SUSE or RHEL for now. You can spin one of these up and install Oracle DB on them.  There are ways to convert a PV AMI to  HVM AMI, but whether Oracle will support you is another question.   This applies to the other cluster compute instances types as well: CC2 and CG1.  However, it is mostly likely someone wants to run the cr1 instance type as this is the largest memory footprint by far (244 GB).  This size instance is great for in memory databases or large EBusiness Suite/Fustion installations.