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It's a critical question facing a growing number of storage managers: hybrid cloud or multi-cloud storage?
In the hybrid cloud vs. multi-cloud showdown, which technology is the best choice? The answer, not surprisingly, depends on the organization and its particular needs. Hybrid cloud storage and multi-cloud storage are terms that are often used interchangeably, but there are distinct differences between the two.
Any type of cloud storage has certain common characteristics, such as optimized storage resource consumption, dynamic storage provisioning, high availability, automatic storage balancing and dynamic storage cluster capacity extension, said Gaurav Yadav, founding engineer at Hedvig, a distributed storage platform provider. "To keep things simple, we define hybrid cloud as storage spread across at least one on-premises data center, as well as at least one public cloud," he said. "Multi-cloud is spread across more than one public cloud vendor, so enterprises can pick any public cloud for the storage requirement and move data across these cloud vendors when needed."
Comparing performance and cost efficiency
"Performance completely depends on the storage vendor's deployment architecture along with the network bandwidth and latency across different on-premises and cloud locations," Yadav said. "For now, hybrid cloud storage is the more practical and safe approach, and the multi-cloud approach is more suitable for small and secondary storage requirements."
Greg ArnetteTechnical evangelist, Barracuda Networks
While the hybrid cloud vs. multi-cloud storage debate is a common one, comparing the two isn't so simple. "Hybrid and multi-cloud are not an apples-to-apples comparison, but in general, hybrid cloud will be more expensive than multi-cloud," said Greg Arnette, technical evangelist at Barracuda Networks, a cloud-enabled security and data protection provider. "This is because hybrid cloud requires extra bandwidth and infrastructure expenses to support managing data in more than one cloud environment." On the other hand, the extra expense should be justified by the additional benefits hybrid cloud offers, Arnette said.
Multi-cloud is generally a more cost-efficient approach than hybrid, particularly for organizations primarily using a public cloud. That's because public cloud payments are typically made only for services used; there are no upfront costs as there would be with a traditional data center. "However, when multi-cloud consists of a mix of public/private clouds, your implementation costs go higher due to the need to interface with different storage APIs on the different clouds," explained Emma McGrattan, senior vice president of engineering at Actian, an on-premises and cloud data management provider. In such a case, a hybrid cloud might prove to be more cost-efficient.
A hybrid cloud user must take storage performance into consideration to ensure that the model supports the network latency that exists between hybrid cloud providers. "It's not economically feasible to continuously replicate terabytes of data between clouds in real time for many applications," Arnette said.
Hybrid cloud vs. multi-cloud management
One benefit to hybrid cloud vs. multi-cloud is that a hybrid approach tends to give greater control over data locality, which is a critical factor in minimizing latency. "But it's really a matter of consuming cloud storage intelligently," said Rich Petersen, co-founder and president of JetStream Software, a cross-cloud data management company. "Having flash storage in the cloud isn't going to do a great deal of good if you're accessing it from on-premises systems over MPLS [Multiprotocol Label Switching]."
"There are legitimate reasons a hybrid cloud architecture is the best solution for specific use cases," Arnette noted. Such use cases include data archiving, disaster recovery/business continuity and cloud bursting -- running applications in a private cloud until demand for resources achieves a predetermined level, at which point they automatically fail over to a public cloud service. Organizations should turn to the multi-cloud model for their commodity, back-office services, like email, file sharing, customer relationship management, single-factor authentication and help desks, Arnette said. "There are best-of-breed options in each category."
"A financial institution with existing data center investments and needing to adhere to compliance would be more comfortable with a hybrid cloud approach, as it would not only provide good governance but also leverage existing investments," McGrattan said. Multi-cloud approaches should be carefully designed around security. "Developers need to take extra care, as it's very easy to inadvertently expose sensitive data," she said. Proper training, processes and having a security team can help mitigate this problem. "Multi-cloud provides better scalability at the cost of lower performance compared to hybrid clouds," McGrattan said. "Hybrid cloud offers more control but also comes at a higher expense, as integrating with existing on-prem data centers can be costly and expensive."
In the hybrid cloud vs. multi-cloud equation, centralized management is essential to both. "Enterprises should look for vendors that can provide a common management scheme, either in their solutions or using public cloud security infrastructures, to simplify managing and monitoring ongoing security," Arnette stated.