By Randy Randhawa, Senior Vice President of Product Development at Virtana

If not planned, or even understood thoroughly, there can be many pitfalls to cloud migration. Virtana’s recent State of Hybrid Cloud survey is evidence of this – with 7-in-10 (72%) of the 350 IT professionals surveyed stating that they have had to move workloads back to on-premises, after migrating to the public cloud. And such a high number certainly raises questions.

There are a host of reasons as to why cloud applications are having to be moved back to on-prem, including:

• The migration of applications that should have stayed on-premises
• Technical issues with provisioning for the public cloud
• Application performance degradation
• Wrong public cloud provider selection
• Unexpected costs

But the good news is, these instances and barriers to successful cloud migration can be avoided. Here’s how to not make the same disruptive and costly migration mistakes.

Ensure workloads that should have stayed on-premises aren’t migrated to the cloud

Not every workload belongs in the cloud, which is why many organisations opt for a hybrid cloud approach, keeping some part of their estate on-premises. You need to consider various attributes of different workloads—e.g., data, back end, privacy and security requirements—and their inherent suitability for a public cloud environment. You also need to have clear goals and priorities so you can make the best decision to support your business needs—and you must communicate those objectives and decisions with everyone involved in the cloud migration process.

Finally, you should understand the detailed health, utilisation, and performance characteristics of your workloads in the data center. This baseline provides critical information to help you make migrate-or-stay decisions.

Avoid technical issues by adopting public cloud provisioning

The technical challenges of public cloud provisioning are due in no small part to the sheer number of configuration options available. Added to that is the fact that most of the guidance available focuses primarily on CPU utilisation. While important, it’s not the only factor to consider. You must also take other computing dimensions—such as memory usage, IOPS, and network bandwidth—into account. Additionally, you may have certain conditions that need to be factored in, such as prepaid reservation commitments or certain types of VMs you want to avoid, to name just two examples.

All of these puzzle pieces have to fit together and if they don’t, you’re going to run into problems. You can head this off at the pass with an automated recommendation engine that looks at all the critical dimensions of your workloads over time, within constraints that you set, to provide you with a manageable short list of configurations. From there, you can perform what-if analysis to find the optimal combination. When it comes time for provisioning, you’ll have a no-surprises process.

Maintaining application performance in the cloud

Any benefits you gain by moving applications to the cloud are outstripped if performance slows to an unacceptable level. To prevent this from happening, you first need to create a baseline of on-premises performance, and model representative workloads in your public cloud configurations—before any migration work begins. Baselines are critical because they provide a reference point for comparing workload utilisation and performance in the cloud. You need to ensure your baselines reflect any seasonality to give you the most complete view of the health, utilisation, and performance characteristics of your workloads in your on-premises infrastructure. Then after you’ve moved your applications to the target cloud, you must optimise them to stay rightsized for performance and cost.

Select the right public cloud provider

Picking the wrong cloud provider could be an expensive and disruptive mistake. You may have specific requirements to help you narrow the list of potential providers, but how do you make an apples-to-apples comparison to ultimately select the provider who will deliver the best performance at the lowest cost? The key is to use an automated recommendation engine, as described above, to build the list of comparable configurations for each provider, and then “play back” those workloads before making any commitments.

Avoid unexpected public cloud costs

Too many times companies get a nasty surprise when their end-of-month cloud bill arrives. Sometimes due to an unplanned surge in activity, or increased workloads over time, it’s important to understand potentially costly changes that could occur before your budget is busted.

To do so, a company needs total visibility of how costs could potentially rise. Utilising ongoing cloud optimisation capabilities can provide such visibility, and provide a platform for resources to be adjusted so that bills remain affordable without performance being harme