SearchStorage.com: What is hybrid cloud storage?Zaffos: We describe a hybrid cloud storage solution as consisting of two parts: an appliance that's installed at the customer site and then the actual cloud storage that the local appliance is de-staging the user's data onto. The advantage of taking a hybrid cloud storage approach as opposed to just connecting directly to the cloud is as follows: The hybrid cloud storage appliance actually has intelligence, software and local storage built into it, so the application servers always communicate to the appliance and never directly to the cloud; by being in the I/O path, the appliance is able to increase the effective WAN bandwidth so the application servers believe they have more bandwidth available to them. It's able to mask off link latency, and it's also able to reduce bandwidth charges and storage charges because the appliance is servicing most I/O requests from the application servers locally. Then, when it decides to de-stage data into the cloud, it first deduplicates the data and then it encrypts the data. By deduping the data and encrypting it, it's reducing bandwidth charges, reducing monthly storage charges, and also addressing user concerns about security, which has been a major impediment to the adoption of public cloud storage solutions. SearchStorage.com: What are the most common use cases for hybrid cloud storage? Zaffos: Today the most common use cases for hybrid cloud storage are for off-site backup and archiving. The reason users have been comfortable in using cloud storage for off-site backup and archiving is that it provides an inexpensive means for storing user data off-site and therefore helping to protect against technology and site failures. It's also less latency-sensitive, and it's less bandwidth-sensitive, particularly when the backup is being done off a point-in-time copy. Many cloud storage providers charge not just a monthly storage fee but monthly bandwidth charges; that is, they charge for data moving into the cloud and data being read from the cloud. Given that backups and archives generally have low I/O access densities -- the data's not referenced unless there's some requirement to restore a particular file or as part of a legal discovery process -- the data tends to be fairly inactive. So, the check you're writing for the cloud storage provider tends to be smaller with these kinds of applications than if you were storing data that was very active with the cloud provider. SearchStorage.com: In what ways do you expect the list of use cases to expand for hybrid cloud? Zaffos: As the hybrid cloud storage appliances prove themselves with respect to availability and performance, the use cases should expand to include things like Exchange and SharePoint and also to facilitate sharing data across geographically dispersed sites and potentially even expand beyond that because the effective bandwidth multiplier that hybrid cloud storage solutions are providing today is on the order of 10:1 to 100:1. For solutions to expand more into mission-critical environments, I think it's critical for the public cloud storage providers to increase the guarantees they're offering to their end users. Today, most hybrid cloud users are guaranteeing three nines of availability, but a number of them are discussing increasing those availability guarantees to perhaps four or five nines. Of course, those guarantees will become much more meaningful as the remedies themselves become more meaningful. So, what we see is an evolutionary path to expanding the use cases for public cloud and cloud storage using hybrid cloud appliances well beyond just archiving and off-site backups.
SearchStorage.com: What should an IT shop do to get started with hybrid cloud storage?
Zaffos: The first thing an IT shop should do is identify applications beyond the obvious archive and backup kinds of applications that could benefit from the use of a hybrid cloud storage solution; [for example], applications that can benefit from having more bandwidth and lower latency, applications that aren't mission-critical but may be straining the facilities.The second step would be to evaluate the hybrid cloud storage solutions that are being offered by a number of vendors and short-list them based on who they're partnering with and how they position their products in the marketplace and their ability to provide customer references, which should be part of any due diligence given the relative newness of the technology. The third thing users should do is negotiate acceptance test periods and escape clauses with both the hybrid cloud storage appliance vendor and cloud provider they're working with or would be using to actually store their information. If the technology didn't perform as advertised, or a vendor was having difficulties with code quality or service and support, you would be able to exit the agreement without an undue operational or financial burden.
This article was originally published on SearchStorage.com.
This was first published in January 2011