Last month, Amazon announced EC2 Dedicated Hosts are now generally available. Amazon initially discussed EC2 Dedicated Hosts at its Re:Invent conference in October.
Using EC2 Dedicated Hosts, customers will have the ability to map Virtual Machines (VMs) to a physical host. Amazon has identified the following use cases where customers may want to leverage a dedicated host:
- Bring your own license (BYOL) which allows customers to move workloads where a license may have been embedded into the cost of the software they previously purchased. For some commercial off the shelf (COTS) vendors, they have embedded operating system or database licensing into their product which may have licensing restrictions that prevent customers from moving those workloads to multi-tenant cloud environments.
- Compliance and regulatory restrictions that may impose constraints on workload co-location or requiring an understanding of what other workloads are running concurrently on the same host.
- Usage and licensing tracking which may be a requirement by some vendors when organizations need to prove or restrict the number of cores, memory or storage that may be available to a particular application.
- Control instance placement will provide customers with granular control over the allocation of EC2 instances within their dedicated hosts.
Customers can provision EC2 dedicated hosts through the typical AWS tools including:
- AWS Management Console
- AWS Command Line Interface (CLI)
- AWS Tools for Windows Powershell
- AWS SDKs
When customers provision their dedicated host, they have the ability to specify the instance type, availability zone, enable auto placement and the quantity as illustrated in the following image.
Image Source: https://aws.amazon.com/blogs/aws/now-available-ec2-dedicated-hosts/
Currently, M3, M4, C3, C4, G2, R3, D2, and I2 are all supported instance types and EC2 Dedicated Hosts are available in US East (Northern Virginia), US West (Oregon), US West (Northern California), Europe (Ireland), Europe (Frankfurt), Asia Pacific (Tokyo), Asia Pacific (Singapore), Asia Pacific (Sydney), and South America (Brazil).
Customers have the ability to import existing virtual machine images onto their dedicated host using VM Import or AWS Management Portal for vCenter. Other options exist for provisioning a VM instance including selecting an Amazon Machine Image (AMI) from the AWS Marketplace including Red Hat Enterprise Linux (RHEL) and SUSE Linux.
When a VM instance is provisioned, there is an Amazon VPC requirement for each VM instance as Jeff Barr, chief evangelist at Amazon, explains “instances launched on a dedicated host must always reside within a VPC. A single Dedicated Host can accommodate instances that run in more than one VPC.”
For customers who want certainty that a VM instance is always running on a particular dedicated host, they can set an affinity flag when provisioning their VM instance. Barr positions the benefit of this feature as “a persistent relationship will be created between the Dedicated Host and the instance. This gives you confidence that the instance will restart on the same Host, and minimizes the possibility that you will inadvertently run licensed software on the wrong Host.”
For many customers, running EC2 Dedicated Hosts will change the way they think about billing. In most cloud billing models, including AWS, customers are used to paying only for compute resources they are consuming. In case of Dedicated Hosts, billing begins once you provision your hosts regardless of the utilization of that host.