What you'll learn in this tip: Implementing hybrid clouds in your data storage environment can be done in three different ways. We provide the details on the various cloud software options you can choose and help you learn which one is best for your organization.
Hybrid clouds come into play when traditional storage systems or internal cloud storage are supplemented with public cloud storage. To make it work, however, certain key requirements must be met. First and foremost, the hybrid storage cloud must behave like homogeneous storage. Except for maybe a small delay when accessing data on the public cloud, it should otherwise be transparent. Mechanisms have to be in place that keep active and frequently accessed data on-premises and push inactive data into the cloud. Hybrid clouds usually depend on nimble policy engines to define the circumstances when data gets moved into or pulled back from the cloud.
There are currently three routes you can take to implement hybrid clouds:
- Via cloud storage software that straddles on-premises and public cloud storage
- Via cloud storage gateways
- Through application integration
Cloud storage software implementation
Combining private cloud storage (on-premises) and public cloud storage into a single heterogeneous storage cloud without custom integration or gateways is only possible today if the internal and external storage clouds run the same cloud storage software. While there are standardization initiatives in progress, such as the Storage Networking Industry Association (SNIA) Cloud Data Management Interface (CDMI), a lack of standards has prohibited out-of-the-box integration between heterogeneous storage clouds. So what we're seeing is cloud software vendors selling their offerings to corporations and service providers to create the prerequisite for hybrid clouds. And some cloud storage providers are offering their storage stacks as internal storage clouds that provide easy integration with their public storage cloud services.
An example of the latter is Nirvanix Inc. Until recently, Nirvanix was only available as a public cloud service, but with the Nirvanix hNode internal cloud storage introduction users are now able to run Nirvanix cloud storage internally and complement it with Nirvanix Storage Delivery Network cloud storage as needed.
Rackspace has been offering its Cloud Files as a public cloud storage service, but it has now open sourced Cloud Files and formed OpenStack.org to drive standardization. The intent is to enable hybrid clouds between service providers and corporate customers, as well as Rackspace Inc.'s public cloud storage service.
Until recently, cloud storage service providers had to either use one of the open source cloud storage products, such as Luster and MogileFS, with their idiosyncrasies and limitations, or develop their own solutions. In the past couple of years, however, cloud storage software has become available as a commercial product from several vendors who sell it to both enterprises and service providers.
Among the commercially available products, EMC Corp.'s Atmos is the most prominent. It's a software-based, hardware-agnostic, object-based storage stack that consists of three loosely coupled services: a presentation layer that handles interfacing to clients via REST, SOAP and traditional file-system protocols; a metadata management layer that manages where data objects are stored and how they're protected and distributed on storage nodes; and a storage target layer that interfaces with storage nodes. It can run on dedicated hardware or on VMware virtual machines. Architected as a scale-out system, it's able to scale to petabytes of storage by simply adding nodes. EMC sells Atmos to enterprises and providers, so on-premises Atmos deployments can federate with Atmos services in the cloud.
EMC's most prominent customer is AT&T. The AT&T Synaptic Storage virtual private cloud, however, is a hybrid storage cloud offering that's quite different from others. It runs in AT&T data centers, but is accessed by customers through AT&T's MPLS network. As a result, it combines security and performance of private clouds with the economics and scalability of public cloud offerings.
Besides EMC Atmos, there are several other cloud storage software products. Caringo Inc. brought CAStor Content Storage Software into this market by repositioning its content addressable storage (CAS) product as a cloud storage solution. Cleversafe Inc. offers a cloud storage platform that leverages information dispersal algorithms (IDAs) that slice data across nodes in the cloud, eliminating the need for replication; Cleversafe claims it has achieved substantially higher storage utilization than products that have to store multiple copies of data on storage nodes for redundancy.
Cloud storage gateways implementation
Cloud storage gateways sit between on-premises storage and public cloud storage. They translate between traditional storage protocols and the more esoteric cloud storage protocols and APIs. Historically, public cloud storage could only be accessed via custom integration. Furthermore, cloud gateways perform data migration of information from on-premises (private) storage into public cloud storage and vice versa, usually via policy engines.
Cloud storage gateways differ in several key areas. They're either block or file based; and they present themselves within the data center as block-based storage or NAS devices. Data deduplication and compression are critical cloud gateway features, as both features significantly impact cloud storage cost. Encryption of data in-transit and while stored in the storage cloud is a must. Some gateways are designed and optimized for backup and archival, some are closely integrated with applications like Microsoft Exchange and SharePoint, and others are targeted as a transactional cloud storage tier to supplement internal storage tiers.
Application integration implementation for hybrid clouds
All public cloud storage services offer APIs to interact with internal cloud storage software and cloud gateways, but these APIs can also be used to directly integrate applications with public cloud storage. Cloud storage APIs enable custom in-house and commercial applications to tap into public cloud storage via REST interfaces.
For instance, backup application vendors have started to add public cloud storage support to their backup suites. Symantec Corp. offers cloud storage support for NetBackup and Backup Exec. Similarly CommVault's Simpana backup software integrates with public storage clouds.
Whether you choose to implement hybrid clouds via cloud storage software, cloud storage gateways or through application integration, all are viable options with several providers and products to choose from. Be sure to weigh your options and choose the hybrid cloud approach that best suits your storage environment.
About the author:
Jacob Gsoedl is a freelance writer and a corporate director for business systems. He can be reached at firstname.lastname@example.org.
This article originally appeared in Storage magazine.
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