Business agility, efficiency, innovation, cost reduction, staying ahead of the competition are some of the compelling reasons for enterprises to go out for the large-scale migrations to the cloud. Enterprises cutting across the industries all over the globe
are replacing their existing legacy, on-premises technology with highly flexible, scalable, and cost-effective computing power in the cloud.
The perceived business benefits of cloud are as massive but realizing them is possible only if enterprises can successfully move their on-premises IT infrastructure to the cloud without any shortcomings and challenges. It’s important that it’s less about
selling your enterprise on the value of the cloud and more about figuring out how to realize the value and benefits promised by cloud adoption.
For many enterprises, first approach towards the cloud adoption is to target low hanging fruits by way of choosing an easy cloud migration approach to realize faster benefits without taking much risk. While there are many migration strategy options are available
(commonly referred 6/7 R disposition) to choose from, “Rehost” also called as “Lift and Shift Migration” migration strategy has become de facto choice for majority for the enterprises to start their cloud adoption journey.
Looking back, last few years of cloud migration journey for many enterprises, lift and shift to begin with looks promising strategy for at the beginning, however in the long run most of the cases it has become anti-strategy due to inability to realize perceived
benefits of cloud adoption. Does “Lift & Shift” really work and deliver the promises, or one must be selective and mindful when deciding to go for this strategy. Let’s go deeper together to understand what works and what doesn’t work with the “Lift and Shift”
cloud migration strategy.
What is “Lift and Shift” cloud migration?
In simple layman terms, Rehosting or lift and shift migration required moving a copy of an existing application and data as they run on your on-premises data centers to cloud infrastructure with minimal or no redesigning, or modification. As it involves
no change to application architecture and little or no change to application code, the lift and shift strategy enables a faster, less laborious and less-costly migration compared to other migration strategies.
When should enterprise consider “Lift and Shift” cloud migration strategy?
- When you are looking for quick wins to save the cost, improve agility, use power of cloud - Situations like DC cost going up due to upcoming hardware refresh or licensing renewal is around the corner and there is dying need to look out for the cost-effective
- Enterprises beginning their cloud journey and they don’t have many engineers with the right skill sets to work in a cloud-first environment, rehosting migration becomes first choice.
- Workloads like company off-the-shelf applications (a.k.a third-party software), that can’t be rearchitected, are best case for lift and shift migration. workloads that are already on virtual machines, containerized applications, an application built on
microservices architecture are the candidates for lift and shift migration.
- Business not ready - enterprise is paying very high infrastructure costs and at the same time not ready to rearchitect or refactor existing IT systems and applications due to business reasons. In such cases, briefly ‘parking’ the applications on the cloud
using lift and shift migration can be considered and in future when business is ready, consider other migration options.
- Applications with dependency on legacy technologies with no matching PaaS services available on cloud are best cases for lift and shift migration.
- Highly security intensive applications that can be consider for PaaS migration as most of PaaS services are multi-tenant in nature becomes candidate for Rehosting.
Reasons why Lift-and-Shift turn out to be anti-strategy for enterprises
While lift and shift might work well in few use cases, it is essential to understand the challenges and shortcomings of this migration strategy brings along with.
- Choosing lift-and-shift alone will not produce desired cloud adoption benefits. An application that’s only partially optimized for the cloud environment may never realize the potential savings of the cloud and may cost more in long run (to an extent of
over 15%). As per Gartner, 80% of organizations conducting a “lift-and-shift” migration in year 2020 for internal business applications from their own data centers to public cloud IaaS will not achieve meaningful cost savings.
- Rehosting often reproduces inefficiencies by designing for the peak capacity, since it recreates what was deployed on-premises. Many a times migrated applications might become slug and unresponsive and run inefficiently while pulling additional resources.
- Unidentified dependencies during the migration can introduce latency post migration to cloud, this can be an issue with shared dependencies like database servers.
- Mirroring (a.k.a mirror migration) is commonly used technique in lift-and-shift cloud migration wherein application, data, and operating system on the source side is copies to a virtual disk file on target cloud. Mirroring often comes with challenges like
ownership issues, image break issues, compatibility issues.
While the above list is not a very elaborative one, it doesn’t mean that lift-and-shift cloud migration never be considered. For many enterprises this can be a good starting point, but in longer run its worth reconsidering the combination of migration strategies
should be the way to go. Many enterprises who have started with lift-and-shift cloud migration as the first step have taken a step back to rethink and re-strategize their long-term cloud adoption journey.
Alternative strategies to Lift and Shift cloud migration
Lift and shift cloud migration strategy is based on Infrastructure as a Services (IaaS) migration model, wherein enterprise is simply moving the applications from on-premises infrastructure to cloud infrastructure to realize benefits from cloud adoption.
By this time, we very well know that this approach has some serious flaws and it’s not the best strategy for enterprises in long run towards their cloud adoption journey.
To realize the full potential and benefits, two alternative migration strategies an enterprise can consider.
- PaaS (platform as a service) Migration - This essentially requires refactoring or re-platforming an existing application, making small changes to optimize performance for the cloud to leverage specific cloud capabilities without changing the end customer
experience. In feasible cases, rearchitecting the application before migrating to cloud to realize full benefit of cloud-native technologies (e.g., microservice architecture with services exposed as APIs, containers, or serverless architecture). Compared to
lift-and-shift migration, PaaS migration is costly, time-consuming, and labor-intensive up front, but it enables the application to take full advantage of the cloud-native feature and PaaS services resulting in overall cost-saving and efficiency in the long
- SaaS (Software as a service) Migration - This essentially requires replacing your on-premises application with a ready-made cloud-based alternative (e.g., replacing existing payment application with cloud-based off-the-shelf payment application) providing
similar functionality and at the same time leverages benefits of your cloud provider’s infrastructure. Right SaaS migration can deliver the benefits of low migration cost of the lift and shift with the cloud advantages of PaaS migration to an extent, but one
needs to adapt to features and customization of SaaS solution.
Making a final decision: Is Lift and Shift cloud migration is right migration strategy for enterprises?
Cloud migration projects are very challenging, as they tend to take up a lot of political and business capital and comes with very high opportunity costs. While lift and shift cloud migration strategy can be a good steppingstone, its highly advisable that
enterprises must weigh the pro and cons of lift and shift migration strategy considering based on not only their current business goals but future business roadmap to determine whether they should dedicate their time, effort, and cost into the lift and shift
cloud migration strategy or look beyond this strategy and consider combination of best fit cloud migration strategies.