How do I migrate my public cloud data back to on-premise storage?

With the adoption of cloud computing, and more specifically cloud storage, on the rise, companies can now easily look to reduce the cost and complexity of their applications and associated data. The economies of scale and shared infrastructure allow service providers to deliver cloud-based storage at a very low cost, compared to traditional on-premise storage platforms. Currently, the popular cloud storage use cases tend to be infrequently accessed data scenarios such as archiving, backup, DR, and offsite data protection.

But what happens when a company decides it wants to move its data and applications back to the on-premise storage platform? Del Lunn of GlassHouse Technologies talks us through the biggest challenges.

Public, hybrid or multi-cloud?

First of all, in the case of the public cloud it is probable that your company will have data hosted with various cloud vendors in a hybrid or multi-cloud model. Hybrid models, however, tend to bring different contractual obligations and interoperability issues, with the need to deal with different SLAs, toolsets, APIs and management infrastructures. So migration back to the on-premise storage could well be a challenge purely in terms of dealing with several vendors, leveraging APIs and tooling for each different service provider to enable the data migration.

Information grows

Secondly, the likelihood is that any migration of cloud data back to an on-premise storage platform will take place over the Internet. Any data hosted with the cloud service provider may well have grown substantially over the course of your contract (many large enterprises deal with petabytes of data) and this data may indeed be accumulated from many locations or clients over many different Internet sources. Depending on the size of the data being migrated, there could be a real challenge for your business in terms of bandwidth, timescales and cost.

Scale, scale, scale

Finally, if the above hurdles can be overcome, a major challenge for your company will be where to locate the migrated data and still ensure that the same feature sets and levels of service as can be attained in the cloud can be met. Each cloud provider will have developed specialist toolsets and invested in hardware and software components at economies of scale that any end user company will probably find impossible to match. The likelihood is that there will be a large capex cost attributed to moving back to on-premise storage, as an investment will be required to the on-premise storage platforms, software and toolsets to meet the capacity, feature sets and service that has been provided by the cloud service providers.

Messy data divorce

In a nutshell, once your data has been transitioned to a cloud service provider it may or may not be technically feasible to migrate it back to on-premise storage, based on the individual scenario. However, organisations are certainly going to have to find a compelling business case for such a migration, since the cost of on-premise storage, toolsets and migration services will almost certainly provide for a less efficient, less flexible and cost prohibitive solution when compared to data storage in the cloud.

Before your company migrates its data to public cloud storage offerings, it is highly recommended that you thoroughly understand the ramifications of transitioning data back to on-premise storage or to another cloud provider. A watertight 'prenuptial agreement' should be in place outlining both the commercial and technical requirements for transitioning back your firm's data, otherwise things could become very messy, just like a bad divorce.

Del Lunn is a principal consultant at GlassHouse Technologies.

Bottom image credit: Flickr (Damien Pollet)