The advantage--and disadvantage--of IaaS cloud computing is complete control. The user is responsible for sizing, installing, and maintaining operating systems and applications, backing up the systems, etc. This enables the user to configure everything in an optimal way for the workloads that need to be accomplished, but it requires time and effort to determine how it should be set up, secured, etc. With the goal of providing a good place for you to start your IaaS implementation and highlighting some areas that you should plan for and design for, Global Knowledge instructor John Hales provides a review of IaaS, as well as insight into what you need to know before implementing IaaS. He also shares a laundry list of things to consider when implementing IaaS, including questions to ask yourself, your company and your potential cloud provider.
Review of IaaS Clouds
IaaS clouds provide the infrastructure (physical or virtual servers, networking, and storage) in a manner very similar to what was and is done in a typical data center deployment with traditional applications. The user has complete control over all aspects of the infrastructure (subject to the capabilities of the provider), including network speed, number and speed of CPUs, amount of RAM, type of storage, etc. The user can fully configure the operating system, applications, etc., and can tune it as desired. In short, it is much like deploying a physical or virtual server on premises today, except it may not be on premises and you don’t pay for it all up front. You pay for it as you use it.
The advantage-and disadvantage-of this cloud type is complete control. The user is responsible for sizing, installing, and maintaining operating systems and applications, backing up the systems, etc. This enables the user to configure everything in an optimal way for the workloads that need to be accomplished, but it requires time and effort to determine how it should be set up, secured, etc. One advantage of using an IaaS cloud instead of a traditional deployment, however, is that if conditions change (for example, there are many more or fewer users than expected or latency is higher than desired), the configuration can be rapidly changed to meet the changed conditions without wasting the large capital expenditures already made or requiring new capital expenditures. The design can literally change hour by hour, month by month as needed.
In this model, networking is always shared in some fashion on the cloud provider’s infrastructure with other consumers, and storage often is (though doesn’t have to be) shared. In many designs, compute may also be shared via the use of virtual machines (VMs), but some providers offer the ability to dedicate CPU and/or memory to specific VMs (not over-provisioning them) and/or a bare metal server, dedicating physical servers to customers.
Services that are Similar to IaaS, but for Specific Purposes
Some aaS categories don’t fall neatly into one of the three broad categories (IaaS, PaaS, and SaaS) but seem to fit best here as IaaS providers.
Disaster Recovery aaS
Disaster Recovery as a Service (DRaaS) is a great option for many companies that only have a single data center. They may be happy with their existing operations but just want to back up to the cloud (or they may want to have the ability to resume operations in the cloud in the event of an outage in their data center. Typically, the cost for this is the storage cost of keeping the data (and usually VMs) available in the cloud and the network cost to replicate the data from the existing data center to the DR location in the cloud. Usually there is no, or very little, compute cost, as the VMs are usually left in a powered-off state, but this isn’t always true, depending on the replication mechanism chosen, the platform being replicated from/to, etc. If the VMs are powered on and it costs to have them idle in the cloud, consider doing development, QA, or other functions on those servers to make use of them. In any case, this is typically much, much cheaper than opening an entire data center just for DR purposes that will be used only rarely (if ever) in most cases.
Companies that offer products in this area include HotLink DR Express for backing up vSphere to Amazon; Zerto for backup/DR of vSphere and/or Hyper-V to vSphere, Hyper-V, AWS, and a large range of cloud providers; and Sunguard Availability Services, which can support not only VMs, but AIX and other physical platforms as well.