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Step-by-step Guide on How to Conduct On-Premise to Cloud Migration

Step-by-step Guide on How to Conduct On-Premise to Cloud Migration
Step-by-step Guide on How to Conduct On-Premise to Cloud Migration
Moving IT infrastructures to the cloud is a complex process and often hinders the development of a company. How does moving to the cloud work, what is the reason for migrating, and in what order is the work done? Let's consider the main aspects of moving the IT infrastructure and the benefits for the company.

Cloud Business

Companies decide to move to the cloud for various reasons. Advantages of cloud migration are obvious: there are no load restrictions and no difficulties with adding new projects. Constant updating of services allows you to instantly respond to new business requirements. However, it is most commonly done to optimize costs and scale, run applications with powerful performance, and reallocate workloads. The key points of migration to the cloud are:

  1. Flexible business scaling. Cloud infrastructure migration is always about development. A growing business that requires more resources needs an environment where these resources are available on-demand and as quickly as possible.

  2. Meeting customer expectations. Moving to the cloud should not be the end goal for the leaders of the company or its IT department. The real expectations and needs of customers come to the forefront. Why are services in the cloud more profitable for them? How will they be able to use new advantages? Won't they face new problems? These questions should be answered before deciding to migrate.

  3. Maintaining business continuity. The manager must understand how critical the downtime of business processes will be, how much it will cost the company, and how to prevent it or minimize risks. There are tools for this in the cloud, plus their numbers are increasing.

Find out more about how migration to the cloud can benefit your business here.

Moving to the Cloud: Basic Tools and Transfer Routes

The beginning of the consumption of cloud IaaS services is often hampered by the issues of transferring the infrastructure or its individual parts to the cloud. To simplify the migration scheme, there is a large list of software and services with which you can transfer almost any workload to the cloud.

In order for you to be able to choose and plan the "move" to the cloud correctly, you need to decide on:

  • source server/virtual machine type;
  • the amount of data that will be transferred;
  • permissible downtime during load transfer.
Based on this information, you can choose the most suitable tool for you. Let's start by looking at the main types of cloud data migration.

P2V (Physical to Virtual)

This type of migration is the conversion of an existing physical server to a virtual one. The need for this arises primarily in enterprises, where the evolutionarily developed infrastructure, built on separate physical servers, is moving to a virtualization system.

P2C (Physical to Cloud)

Physical to Cloud is also a transformation of a physical server into a "cloud", but with the goal of transferring data directly to cloud IaaS resources. Such a task may appear for companies that are faced with a choice - buy a server or stop investing in capital costs and start consuming resources from the cloud.

V2V (Virtual to Virtual)

Migration between different virtualization systems may be required in the event of a change in the corporate standard when choosing a virtualization system or consolidating an evolutionary enterprise infrastructure on different virtualization systems. Also, this task may arise when deciding to move to the cloud, if the underlying cloud virtualization system does not match the system underlying the customer's infrastructure.

V2C (Virtual to Cloud)

The logical conclusion of this list is the migration of a load of virtual machines to the cloud. The size of the virtual machine is obviously very important for on-prem to cloud movement, and, accordingly, the method by which the data will be transferred. It should be noted that before starting any migration using virtual infrastructure tools, you must analyze your software. Perhaps it has built-in data transfer mechanisms, in this case, it will help you avoid unnecessary migration-related operations.

Benefits of Migrating to the Cloud

Let's talk about the main advantages of migrating IT infrastructure to cloud services, in other words, why companies are moving to the cloud. Many companies are familiar with the benefits. Here are the main ones:

  • simple and efficient use of resources. They are allocated on-demand, in exactly the amount required at the current stage;

  • transparent cost of services. The organization pays only for actually used resources: computing, network, storage. It can plan costs based on business growth;

  • minimum time for IT infrastructure maintenance. Whereas previously a large staff of technical specialists was required, now the same scope of tasks is performed by 1–2 employees;

  • technical support 24/7. Cloud providers solve customer problems in real-time. You can count on highly qualified assistance from highly specialized engineers;

  • simple migration between providers. At any time, you can break the agreement and transfer data and applications to competitors if they offer more benefits;

  • service mobility. In the cloud, data and services are available from anywhere in the world for both the company and its customers. This eliminates the need for complex organizational arrangements when changing a physical address;

  • reducing the risks of service downtime. Cloud providers are interested in ensuring that client resources work without interruptions. To do this, they invest resources (money and expertise) in creating a reliable infrastructure, qualified engineers, make backups, and provide the data center with backup power supplies.

Cloud Migration Best Practices

To make a decision on moving from on-premise to cloud, first of all, you need to assess the capacity and type of infrastructure that the company needs. For this, a list of necessary services is drawn up and the computing power required for the proper operation of each of them is estimated.

The next step is to determine how to move data to cloud storage and when to complete it. Usually, this procedure is performed by the data center since it allows you to upgrade services and perform migration seamlessly - that is, without interrupting business processes.

Some existing systems are not eligible to migrate to cloud computing. Those are:

  • Electronic security keys.
  • Systems that require high performance to operate correctly.
  • Software with licensing restrictions.
  • Services without prior testing.
  • Programs that require physical hardware to run.
  • Systems requiring increased security.
There are 3 main scenarios for cloud application migration:

  1. Full migration. This means that the created infrastructure is transferred from the on-premise to cloud: existing data, applications used, saved settings, etc. At the same time, it is necessary to save or recreate terminal stations through which company employees will gain access to services. This method is usually chosen by small and medium-sized businesses with a fairly simple IT infrastructure. Data transfer and applications migration is done in a couple of days. The approach has minimal risks and requires minimal resources for implementation, but does not always allow for full utilization of the capabilities of the cloud service.

  2. Partial migration to the cloud. In fact, this is a hybrid model that assumes transferring only a fraction of information resources and systems to a cloud service. Some services remain on the organization's own physical capacities for security purposes. This organization model is often chosen for testing and working with cloud technologies. In the case of satisfactory results of the partial migration, the transfer of all information to the new virtual platform is carried out in stages. A so-called roadmap of migration procedures is drawn up, which allows for the transfer of services without delaying business processes. This option is suitable for a large company with several remote offices.

  3. Parallel-optimized migration. Such application migration to cloud implies a simultaneous transformation of the structure of the system. For example, the way applications interact with the database may change. Other changes are also made to take full advantage of the cloud.
In the event of termination of the previous licensing or the repurposing of services, it is also possible to use a new product. This solution is often chosen when migrating email, etc.

Migration Scheme

There is no single time frame for on-premise to cloud migration. The process is built individually and depends on individual criteria. If a seamless migration is needed, that is, a transfer without the downtime of information systems, then this is taken into account at the planning stage and reflected in the work schedule. A company that plans to migrate all or part of its IT infrastructure to the cloud can develop its own migration plan or use a generally accepted scheme. In any case, it needs to be finalized taking into account the specifics of the business, the volume of data, the principles of working with them, the presence of a geographically distributed network of offices, and other factors. The generally accepted scheme can be broken down into several typical steps.
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Inventory allows you to assess the current volume of the company's IT infrastructure, highlight priority components, and establish relationships between them that need to be taken into account in the migration process. During the inventory, you can find problem areas that require maximum attention during the transfer of data and services.


Migration to cloud is available in three models:

  1. Public cloud: The hosting provider provides cloud services to a large number of customers, and the computing, networking, and storage resources are located in one large (or several) data centers. A public cloud is needed wherever flexibility and automation of routine tasks are required. Often the owners of websites and online services, and companies that develop and test software are interested in such a service;

  2. Private cloud: the company builds its own cloud infrastructure and the resources on which the services in the cloud will run belong only to it. Large companies with extensive IT infrastructures and who work with confidential data or the state are most likely to benefit from a private cloud;

  3. Hybrid cloud: a symbiosis of private and public clouds, where the exchange of data between them is strictly controlled by the company. Hybrid cloud is beneficial to use where the business is faced with sudden surges in activity (for example, during sales or advertising campaigns), where it is required to implement complex technological solutions after preliminary testing, where it is necessary to test the operation of IT infrastructure elements or where new software products are being developed.
After choosing the appropriate model for the on-premise to cloud migration, calculate the need for resources: the computing power of the processors, the type and capacity of the drives, the width of the Internet channel, the number of IP addresses, etc.


Choosing a provider is one of the most critical tasks at this stage of preparing for migration. It is necessary to make sure that the provider is reliable, has the appropriate infrastructure, invests resources in its development, offers exactly the services and tools that the business needs. Ideally, the provider gives the opportunity to take advantage of the test period and assess the potential of its site on real or test projects.

Enter into a service level agreement or SLA. The leaders of the cloud market indicate how long the client's services can be unavailable (and this time is minimal) and take on the problems associated with technical and software failures in the data center.


An accurate roadmap will help you plan your application migration to cloud and avoid critical mistakes. It is important to appoint not only the sequence of actions but also the deadline for completing each task. Critical services are transferred when they are least loaded (for example, at night). Ideally, you want the migration to go seamlessly, and clients of the company's services will not notice it.


After completing the previous points, you can begin to transfer data, services, and other intangible components of the IT infrastructure. At the final stage, the work of all systems in the cloud environment is tested and fixed in case errors arose during the migration process. It is important to understand whether the service turned out to be really functional.

Enterprise applications move to the cloud is a phased process that is a collaborative effort between the customer and the cloud provider. In most cases, the move is performed not from hardware, but from a working virtualization system, but, despite this, the process requires special preparation.

Analyzing the application migration best practices, we can single out several main stages. Each of them has its own nuances, and knowing these will help you to avoid making mistakes.

  1. Preparation phase. Preparation begins with an assessment of the existing infrastructure and a migration plan. You need to calculate the exact capacity of the resources that you plan to move to the cloud. Often they may be smaller than what is currently used. Working with your own physical or virtual infrastructure, you build capacity in order to anticipate future growth in business demands, as well as level out optimization flaws that are excluded in a cloud provider environment. Renting a virtual infrastructure allows you to add additional resources only when the need arises, therefore, if you calculated that a certain service requires 2 cores, 16GB of RAM and 500 GB of disk space, then only that much needs to be rented, and when you need to increase performance - adjust the specification.

  2. Transfer plan. It is necessary to create a table listing all the transferred services, specify the consumed resources for each, determine the transfer priority, and the criticality of the stop at the time of transfer. The usual practice is that first, non-critical services are transferred to the cloud, those on which you can test work with a cloud provider, and only after a while the rest of the infrastructure is migrated.
Choosing a transfer method. Basically, the applications migration method depends on the source platform (the type of virtualization in the case of a private cloud migration or an iron server) and data activity (will it be an offline move or it is necessary to transfer hot data). The speed of the Internet channel between the source infrastructure and the cloud provider's data center also plays a role. If the speed or quality of the communication line is low, it makes sense to consider the option of migrating using an external NAS. After the services that will migrate to the cloud have been identified, their power consumption has been calculated, a migration plan has been drawn up taking into account the priority, the data transfer method has been selected and an agreement has been concluded with a cloud provider, you can start moving to the cloud. At this stage, the services are transferred to the provider's cloud. There are many options for how this can happen, each suitable for specific infrastructure.

Example of Migration for a Financial Institution

The best way to understand what is on premises data movement and how it is implemented is to see how others did it. Consider a bank whose management plans to leverage cloud infrastructure to improve business agility and data processing speed. In this case, the migration will consist of the following steps:

  • inventory of stored data and software for their processing on the side;
  • assessment of the possibility of processing them by a third party (the bank is likely to choose a hybrid storage model and keep some of the data at arm's length);
  • choosing a cloud provider that works in the legal field of the country;
  • drawing up a plan for the phased transfer of non-critical information to the cloud to a third-party provider;
  • transfer and testing of services in new conditions, as well as integration with data that remained on the bank's side.
During the inventory, the bank analyzes the data and categorizes it: public, official, confidential, and special (for example, constituting a state secret). In this case, the bank will be able to transfer confidential information to the cloud provider only if the provider has a license.

When Does Cloud Migration Lead to Problems?

Lack of experience makes it easy to make critical mistakes that can lead to negative business consequences. You may be faced with problems if:

  • there is no diagram of dependencies between applications. If individual applications or services use the same database, then they can be moved to the cloud only as a complex, otherwise, the business risks disrupting the usual performance of current tasks.

  • there is no migration plan (roadmap). The plan clearly states what will move to the cloud, in what volume, and in what time frame. This is a sequential description of actions that will help you organize migration correctly, avoid chaos, lost data, and business process interruptions.

  • migration is carried out without preliminary testing. The cloud provider may not be the right fit for the business. To prevent this from happening, request a test period, and familiarize yourself with the service in detail by running a "raw" project in the cloud (not from production!). Evaluate the reliability of the service, how quickly the technical support responds to questions, and whether it is convenient to redistribute resources and perform other actions in your personal account.

The main problem with on premise to cloud migration is the lack of time and subject knowledge for IT services to analyze corporate IT services, standardization, and IT automation. All the advantages of a cloud - efficiency, controllability, consolidation, and security - are rarely directly demanded by the customer. Genuine "cloudiness", semi-elasticity, accounting of a very good solution depends on the maturity and literacy of IT professionals who take part in preparing the transition to the cloud.

Final Word

The final step in cloud infrastructure migration is validating and testing the migrated services. If there are no errors and the services are functioning as expected, they can be put into production. Nowadays, many companies prefer to move their infrastructure to the provider's cloud and use the IaaS model, rather than maintain their own server room. Choosing the right cloud migration strategy and following the best practices will allow you to complete your migration with minimal business downtime.
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