By Mark Weiner, Director of Product Marketing, Microsoft

Cloud storage is one of the hottest segments of cloud computing. Enterprise customers are increasingly looking at cloud storage as a way to leverage the benefits of cloud economics and agility without giving up performance and improving data protection  capabilities. The Microsoft-StorSimple answer is to take a hybrid approach to allow you to extend existing on-premises storage investments while getting the strong benefits of the cloud.

When comparing cloud storage providers (CSP) to create a hybrid cloud storage solution, you should look carefully at both the storage service offering and the on-premises storage component. In the remainder of this blog, I’ll share a few guidelines and differentiators that buyers should look at when evaluating this on-premise storage component.

The first thing to note: CSPs’ on-premise storage components vary widely in architecture, functionality, cloud integration and form factors.  There are huge differences between what are called cloud storage gateways and cloud-integrated storage.  Gateways provide an access point from on-premises to cloud data  transfers, whereas cloud-integrated storage is an automated solution to some of IT’s biggest problems such as managing data growth, backup and recovery, archiving data and disaster preparation.

Gateways – whether offered by cloud providers or standalone vendors – serve two basic functions: 1) caching most frequently used data on-premises, and 2) translating from local to cloud storage protocols and data formats.  Some gateways are configured to serve as a proxy in front of existing storage infrastructure (DAS/NAS/SAN) for the sole purpose of copying data to the cloud, while risking the performance, reliability and availability levels of on-premises data access.

Cloud-integrated storage (CiS), like Microsoft’s recent StorSimple acquisition, is a full-featured on-premises storage system that integrates with the cloud (i.e. Windows Azure Storage).   Enterprises can create a complete hybrid cloud storage architecture where they store their data locally and protect it with snapshots on-premises and in the cloud, and where dormant data can be seamlessly tiered to the cloud to make room for new data locally. This way, CiS gives IT an automated  “safety valve” to prevent running out of disk capacity, while also providing rapid disaster recovery via cloud snapshots.                                                                           

Let’s get a little deeper in this comparison of gateways vs. CiS, and what each solution provides.  A key buying trigger for many IT infrastructure teams is storage infrastructure sprawl – too many devices for data management.  Gateways do eliminate the need for tape backups.  But what they don’t do is further eliminate the need for related backup software + support licenses, as well as the even bigger cost + time requirement of primary storage as data keeps growing at 50-60%+ per year.

The next issue is complexity.  Cloud storage is supposed to *reduce* the complexity of storage infrastructure (along with overall costs).  Yet a hybrid cloud storage solution built with software gateways can actually *increase* infrastructure complexity at even a modest degree of scale.  That’s due to the limitations of software-based gateways with volume sizes (e.g. some maxed at 1TB/stored volume), the requirement for virtual machines (VMs) to host the gateways, gateways per VM (e.g. 12 gateways per VM), lack of integration w/ backup software, etc.

Lastly, buyers should also carefully examine the reliability of different hybrid cloud storage solutions and their on-premise components.  Is the on-premise component an enterprise-level offering, with key storage features like full hardware redundancy, local snapshot
capability, non-disruptive upgrades, etc. – or is it software-only and itself reliant on virtual machines, underlying servers and other layers of potential failure?

Net-net: as you migrate your traditional storage infrastructure to integrate with the cloud – most likely a hybrid cloud storage architecture – look closely at the on-premise system that will be deployed and make sure it fully enables both the savings and data protection goals you have for your cloud storage project + strategy.