Cloud-Like Expenses with an On-Premises Experience

Reality has set in and it’s probably safe to say that the hype about “cloud” has subsided. Business leaders today logically evaluate the benefits of public cloud services and determine where they may be able to improve their product, operations, or bottom line. Sometimes, their assessment is that they like the economic model of certain cloud services, but for other reasons, they need to retain complete control of the infrastructure. In the sober Slope of Enlightenment and subsequent Plateau of Productivity, there are a wealth of options for deploying either on-premises infrastructure with cloud-like characteristics, or technology that marries owned infrastructure with public cloud infrastructure to create a hybrid cloud.

What Do You Really Want?

There are plenty of organizations who are still wallowing in the Trough of Disillusionment because they thought that moving everything to the public cloud was what they wanted; they naively forklifted everything they could into the cloud and soon found out that public cloud services aren’t the panacea they’re often made out to be.
However, there was obviously something that had these innocent IT professionals sold on the idea of moving to the cloud. Perhaps it was the operational efficiency. Certainly, swiping a credit card and having a series of virtual machines available and ready to be put to work within five minutes is an attractive possibility. Or perhaps it was the prospect of geographical diversity for availability’s sake without having to manage data centers worldwide. That’s also a great reason to move workloads to the cloud.
For many organizations, though, one of the primary drivers is economics. Everything always comes back to money, doesn’t it? In the case of moving enterprise data center workloads to a public cloud service, the paradigm shift is pretty dramatic. And the accompanying change to the way IT services are procured, deployed, and maintained is equally significant. A few of the main economic drivers for a shift to the cloud are:

  • To shift what have traditionally been capital expenses to operational expenses
  • To take advantage of consumption-based pricing in the cloud: pay only for what you use
  • To get more bang for your buck because cloud service providers leverage an economy of scale that most other businesses don’t enjoy

As it turns out, many decision makers would actually prefer to not move everything to a public cloud if they could still enjoy the benefits listed above. If there were a way to gain these desirable economic advantages while retaining the experience of on-premises infrastructure or by leveraging a hybrid configuration of on-prem and cloud-based infrastructures, that might be a great option, too!

On-Premises Infrastructure Backed by the Cloud

The marriage of on-premises control and performance with the elasticity and availability of the cloud is happening rapidly now. One of the specific data center technologies that stands to gain the most benefit from this hybrid architecture is storage. If one could consume storage like you would in the cloud (on-demand, pay only for what you use, leverage economies of scale) but keep the access and delivery of that data on-premises (for performance and manageability), you’d essentially have the best of both worlds! I’ve been looking at a few options for this sort of storage architecture, and last week I had a chance to play with ClearSky Data’s on-demand primary storage, offsite backup and DR (all rolled into one service). This is precisely the sort of hybrid conglomeration of on-prem and cloud infrastructure I’ve been describing, and it’s entirely consumed as a  service, so the OPEX and consumption-based economics are intact.

A Brief Platform Overview

The diagram below illustrates how three tiers of storage work in tandem to provide high performance storage with an almost unlimited capacity available on the back end.

The three tiers of storage in a ClearSky Data system

The Hot Tier

An “Edge Cache” device is placed in the customer’s data center. Storage volumes are provisioned and presented from this device and mounted exactly as they would be from any typical block storage array. In ClearSky’s primary use case, you’ll be creating vSphere VMFS datastores attached via iSCSI or Fibre Channel which you’ll use to store virtual machine files. The Edge Cache is an all-flash appliance which has enough capacity to hold the active working set and then some. With a nice large cache, most reads should come from here.

Aside: Until this point, there are plenty of other solutions that do this. It’s called a “cloud gateway,” and even Amazon Web Services offers such a solution. While this does work, latency on a cache miss can quickly degrade the end user experience to point where the solution is unusable for many scenarios.

The Warm Tier

The middle tier, called a Metro Point-of-Presence, holds warm data. “Warm data” is data that has been evicted from the cache, but not yet archived to the backing cloud. This tier is what sets ClearSky’s solution apart from any old cloud gateway.
ClearSky Data deploys storage systems in these Points-of-Presence to provide persistent storage to the Edge Cache. The PoP is less than 120 miles from the Edge Cache; it is directly connected to the data center via leased lines, and latency between the Edge Cache and the PoP is less than 2 milliseconds. As a result, a cache miss at the Edge Cache results in a read from the PoP, which introduces a generally negligible amount more latency. According to ClearSky, somewhere between 95 and 99 percent of reads come from either the Edge Cache or the Metro PoP.

The Cold Tier

Finally, for the sake of durability and retention, data is eventually de-staged from the warm tier to the cold tier which is provided by a public cloud service. By leveraging cloud storage for the cold tier, ClearSky is able to pass on savings from the CSP’s economy of scale to their customers.

Cloud-Like Expenses with an On-Premises Experience

The end result of adoption of a ClearSky Data system is that IT organizations are able to leverage a primary storage system with the experience of residing on-premises in their data center that is paid for, scaled, and available as if it were public cloud storage.

  • Because the gear and platform is owned and managed by ClearSky, storage becomes an operational expense just like it would be if you moved wholesale to the cloud.
  • Pricing is pay-as-you-go and consumption-based, just as it would be in the cloud.
  • Because the cold tier actually IS in the cloud, you’re still able to leverage the availability and economy of scale that public cloud providers offer.

ClearSky’s solution also has very interesting implications for multi-site configurations and DR sites. And there’s some use cases like machine data storage that are especially good fits for a cloud-backed storage platform like this one. I recommend heading over to to learn more!