DATA MIGRATION

DATA 
MIGRATION?

Data migration is the process of transferring data between systems, formats or storage systems. The process may require steps of selection, preparation, extractions and transformation.

For example, you might be replacing servers or storage devices or moving from one accountancy software to another. Data migration is also an essential step in the process of migrating on-premises IT infrastructure to a new environment.

Even when organisations move from one application to another, the target application is normally cloud-based (SaaS). As a result, the issues encountered, and approach required, are similar for most data migration projects.

Whenever you migrate data, your approach will need to protect your data integrity and also be efficient.

DATA MIGRATION 
TO THE CLOUD

Many organisations are choosing to move their applications and data to the cloud in hopes of improving the availability, cost-effectiveness and performance of their IT environments.

The data migration strategy is a key component of the cloud migration planning process and should be considered early in the process.

You can choose among several options for transferring data from a local data centre to the cloud, but broadly speaking, they fall into two categories:

• Online migration, in which data moves across the Internet or a private or dedicated WAN connection.
• Offline migration, in which data is transferred via a storage appliance that’s physically shipped from the original data centre to the new cloud storage location.

Which option you choose will depend upon the volume of data you need to move, the deadlines for completing the migration, the types of workloads involved, and your security requirements.

DATA 
MIGRATION

Many public and private cloud providers offer tools that can simplify or automate parts of the database migration process to ensure that your data remains safe throughout the move and that no data loss or corruption occurs. Additionally, most cloud providers offer migration services to verify your data’s integrity after the transfer.

Normally, the first step in the database migration process, involves converting the source database’s schema so that it’s compatible with the target database. A database’s schema is like a blueprint. It describes the logical architecture, structure and organisation of the data. The database schema will usually need to be updated if the target database is from a different vendor.

The next steps are to migrate the data and set up ongoing incremental data updates. You can also consolidate multiple different databases into one during this process, if necessary.

CONSIDERATIONS WHEN FORMULATING A 
STRATEGY

Through carefully planning a data migration, an organisation can reduce service outages and stay within budgets. It is important to establish goals, set a timeline, and anticipate any challenges that you may encounter.

There are three primary factors you should consider when approaching the project:

• Type of workload: There are usually vendor-specific tools to help with migrating databases and backups. If you don’t have access to these tools, you may need to plan outages to transfer the data. You can migrate data for mission-critical systems in stages, testing at intervals throughout the process and keeping the source and target systems running in parallel. 
  Alternatively, you can plan a bulk transfers outside of production hours, if the availability window permits.
  
• Volume of data: In theory, you could use online migration for any amount of data, but time constraints limit the transfers of large amounts of data. For volumes of data up to 10 terabytes (TB), the simplest and most cost-effective method is to use a client-provided storage device.
  For migrations involving higher volumes of data, most cloud providers will supply a specialised data migration device. 
  
• Speed to completion: For online migrations, the amount of data being transferred and the speed of your network connection will determine how long data migration takes. For offline migrations, shipping time must be taken into account. Online transfers can be the best option if you have sufficient network bandwidth, for the volume of data you require to migrate, otherwise offline migration is the right choice. 
  

Which option you select for your data migration project depends upon how much data you need to move, the deadlines for completing the migration, the types of workloads involved, and your security requirements.

BEST 
PRACTICES

To ensure that your project goes smoothly, adhere to the following best practices:

• Verify business requirements early in the process:What kind of migration timeline is necessary? If an application is being decommissioned, when will its license expire? What kind of data security is required throughout the migration? What level of data loss or corruption is tolerable – if any? Will business processes be changing? 
  
• Understand the data and what it is used for: Who are the users of the data? Will it be the same users in the future? How is it currently being used? How will it be used going forward? Try to gather information from all relevant stakeholders and business units throughout the migration process. There may be opportunities to do a spring clean on the data you have accumulated.
  
• Assess the source and target environments carefully: Will there be a change in operating systems? Will database schemas or other formatting need to change? Will any data redundancy need to be addressed?