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Even with the array of software-defined storage and storage virtualization options available today, storage is still storage. Your VMs are not going to get any smaller, nor are they going to decrease in quantity. Organizations with existing storage frames have the experience with dedicated frames and storage networks. While this investment in hardware and personnel is often considerable, there's something to be said for consistency in both reliability and performance. Still, it's worth noting that features such as data mirroring, deduplication, encryption and disaster recovery options are now being offered in hyper-converged infrastructure products.
The converged infrastructure movement
The advent of converged and hyper-converged infrastructure makes it confusing to know which storage for virtualization paths might be ideal for the present and still enable you to progress into the future. To make good decisions, you'll want to understand the differences between hyper-converged and converged infrastructure and what role traditional storage still plays.
- Converged infrastructure. This is having the compute, networking and storage as building blocks that are preconfigured and put together in a defined system. Since it's based on existing vendor building blocks, a converged infrastructure scales quickly, and expansion is reasonably simple as long as it is done with another certified block. The upfront cost of the preconfigured product is significant, because you're paying for the technology as well as the vendor's work integrating the components. But the expectation is that total cost of ownership looks favorable in subsequent years. Users have some flexibility to change or upgrade the building blocks, but only to the extent allowed by the converged infrastructure vendor. In a converged infrastructure, the storage controller is still hardware-based and controlled by the "traditional" storage area network (SAN) or network-attached storage (NAS) block of the solution. This resembles more of the traditional data center elements enclosed in a dedicated pod.
- Hyper-converged infrastructure. The hyper in the converged infrastructure category signifies taking the benefits of the converged infrastructure and adding an additional layer of software to bring the collection of compute, networking and storage into a single package rather than a collection of blocks. With products such as Nutanix or EVO:RAIL, vendors have removed the storage controller from the storage hardware and turned it into a software service that operates at the hypervisor layer. Shifting the storage controller into software allows for greater flexibility into what can be done. This type of decentralized storage technique reduces the complexity of a dedicated storage frame and network. And it allows for lower cost local storage while enabling higher-end features such as replication and deduplication.
Converged and hyper-converged infrastructure products have been gaining a lot of attention because they can solve a storage problem for certain types of organizations. When trying to use a standard server for a storage platform, there are concerns about hardware durability and performance. Those can be addressed by applying software-defined storage features on a hyper-converged infrastructure that's designed to handle a virtualized environment's workloads.
What SDS can do for you
Software-defined storage and storage virtualization provide an organization with a lot of capabilities. Which of those an organization chooses to apply is a decision often driven by its existing infrastructure and what it's looking for in storage or virtualization. Organizations with traditional storage frames may not be looking to forklift and replace those existing frames. Instead, they might be inclined to leverage them by adding new functionality found in a software-defined storage tool. The same can be said for companies looking to adopt an enterprise application requiring dedicated bandwidth sharing a traditional SAN/NAS. Using these technologies with your virtualization infrastructure is a proven method. The struggle will be trying to find a way to do it with a cost-effective cost per gigabyte.
Storage for virtualization solutions are as unique as the environments they need to support. While no one doubts the value of virtualization, where the hypervisor should reside is a matter of debate.
Storage has not yet become a commodity like the compute platform has. An organization needs to evaluate criteria on cost, complexity, reliability and performance.
Evaluating the storage for virtualization options
|SAN / NAS||Very high; because of dedicated networking and the storage frame itself||Very high; requires dedicated staff and training in the storage frame and storage network||Very high; the frames are capable or multiple levels of redundancy||Very high; the storage frame has the ability to be configured for high and dedicated IOPS|
|Local Storage||Low; 10 GB network needs still do not offset the savings of using server class drives||Low; products are often hypervisor-based or an appliance, with limited configuration options||Medium; protection is through a combination of local and network RAID||Medium; its base is a server platform and not a dedicated storage platform|
|Converged Infrastructure||High; because of the dedicated storage frame (even though it's included in a bundle)||Medium; the pieces are separate blocks, but they have been designed to work together||Very high; the storage block in converged infrastructure is often the same as in a dedicated SAN or NAS||Very high; the storage frame has the ability to be configured for high and dedicated IOPS|
|Hyper-Converged Infrastructure||Medium; using server-class drives is a savings, but some of that is offset by the platform costs||Low; a single pane of glass to manage, provision and monitor storage||Medium-high; platforms offer local storage capacity and performance, distributing it across multiple nodes||Very high; the storage controller is a service in a dedicated platform designed for heavy I/O|
From a storage perspective, the hyper-converged platform stands out. Bringing together compute, networking and storage into the same platform is an ideal move from a hardware aspect. Also, moving the storage controller from a hardware component to a software service (controllable by the administrator without requiring excessive training) was a logical and welcome step.
As you look at the future of your data center, virtualization and its storage appetites stand out as key trends. Nutanix has been a market leader in hyper-converged infrastructure. Vendors such as Dell, HP and Fujitsu are working with VMware for VMware's EVO line of hyper-converged products. Even big storage players such as EMC, NetApp and Hitachi are working on hyper-converged infrastructure. While trying to predict the future is always a tricky proposition, it seems clear that with storage, vendors understand that their products need to better balance cost, flexibility and performance. As customers, we have many options, but there is a lot to like about storage in a hyper-converged context.
Prudent IT planning covers a lot of territory. Virtualization, cloud computing and storage are at the heart of these discussions. You'll want to anticipate what's coming next in these areas, so that you are, in effect, future-proofing an infrastructure and making choices now that leave you in position to adapt later.
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