Office 365 Migration Planning

Why move to Exchange Online?

With Microsoft Exchange being the leader in business email in the market, most of the corporates (small and big) use it pervasively for messaging and collaboration. Though widely used, the Exchange server platform has become increasingly complex to manage and maintain over the years. A reliable Exchange infrastructure involves server maintenance, upgrade of software and hardware, daily Exchange and Windows backup and seamless mail flow. This requires a dedicated IT department equipped with the necessary Exchange and Windows infrastructure expertise to keep it running smoothly.

With the advent of Office 365, one of the main goals of Microsoft is to assist organizations in moving their on premise Exchange workload to the cloud in order to remove the burden of managing the Exchange infrastructure. Many organizations worldwide have started to move from Exchange on premises to Exchange Online. While it is certainly a huge benefit to move messaging services to the cloud, it is not an easy task to dismantle exchange servers that are holding terabytes of messaging content for over several years, without proper planning and execution process.

Understanding what’s involved prior to moving to Exchange Online

With so much information about various migration options provided by Microsoft, it becomes a knowledge intensive process to migrate to Exchange online. Most of the concerns are around preparation, planning and the actual automated process of migrating mail data. It takes significant project management skills to come up with a rough estimate of the time taken to get the Exchange Online framework up and running.

No company management would allow any downtime during business hours, especially messaging related to Sales, Support and other external communications. So there are quite a few points (like, knowing about Exchange infrastructure, connectors, mailboxes, groups, unwanted resources) to be considered before even planning Office 365 migration.

The following broad set of tasks may be considered while assessing the impact of migration:

  • Visibility & Discovery – Do IT administrators have complete visibility of all aspects of Exchange servers, Windows network, Active Directory and other related server platforms? Discovering and Understanding what is currently out there on premises is the first step.
  • Cleaning up the clutter – It is a great one-time opportunity during cloud migration to get rid of unwanted elements in the on premise IT infrastructure before moving to the cloud. Preparing a list of essential elements that need to move to Exchange online will remove bloat and optimize the migration.
  • Restructuring – A more prudent approach would be to actually reorganize all aspects of the exchange infrastructure on premises and come up with a plan to take advantage of some of the inherent capabilities of Exchange online, such as Security and Backup.

Understanding the nuts and bolts of Office 365 migration

Exchange Mailboxes & Public Folders

In the Exchange setup, mailboxes, distribution groups, contacts and public folder are the ones, which the end users (employees) will deal with it on a daily basis. Of these, Mailboxes and Public Folders are most the frequently accessed and both of these occupy a significant chunk of server data storage.

In the context of moving to Exchange Online, these objects have to be studied extensively for better Office 365 setup, as stated below.

  • Clean up unwanted mailboxes and/or its contents
  • Clean up Active Directory
  • Defragment mailbox and public folder databases
  • Conversion of mailboxes to new alternatives available in Office 365 (like, shared mailbox)
  • Adherence to Exchange Online limits and limitations

What’s your Migration Strategy?

For Exchange on premise to Exchange Online (Office 365) migration, Microsoft provides various Office 365 migration paths for users to choose based on their usage scenarios. For example, from Exchange 2010/2013 to Exchange Online, you can refer the below table:

Exchange 2010 or Exchange 2013

If your source system is Exchange 2010 or Exchange 2013, consider the following options.

Note: Even though cutover migration supports moving up to 2000 mailboxes, due to the long time it takes to create and migrate 2000 users, it is more reasonable to migrate 150 users or less.

Number of mailboxesHow quickly do you want to migrate?Use
Fewer than 150Over a weekend or a few days.Cutover
Fewer than 150Slowly by migrating a few users at a time.Exchange Hybrid
Over 150Over a weekend or a few days.Exchange Hybrid
If you have more than 150 mailboxes, the best method is to use an Exchange hybrid migration where you can migrate a limited number of users at a time. This is because cutover migration performance suffers when you try to migrate more than 150 mailboxes.
Over 150Slowly by migrating a few users at a time.Exchange Hybrid

How to go about doing this?

In moving to Exchange Online, large organizations would normally hire consulting companies (who are into this profession as hard-core business) to analyze their infrastructure, review their migration approach and execution plan, and then sign off to perform the actual migration.

As SMEs cannot afford to hire third party consultants, they will try to use their local Exchange admins to perform the migration. The admins might use either Microsoft’s native Exchange migration methods or purchase third party commercial tools to perform the migration. In this case, it is the responsibility of the admins to ensure zero or minimal downtime and smooth completion of migration.

Irrespective of how the migration gets carried out, the very first phase of planning the migration requires that personnel in charge of migration get a complete overview of existing Inventory in Exchange servers and Active Directory and then perform an analysis of this inventory to determine what gets into their Exchange Online.

For this purpose, Vyapin has come out with a useful Office 365 migration planning tool to assist Administrators, Consultants and other third-party migration vendors to perform the essential planning steps of Discovery, Inventory Analysis and Preparation, prior to carrying out the migration.

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For any project implementation, proper planning is required. A detailed analysis of Exchange infrastructure on premises forms the backbone for efficient planning of Exchange Online migration. Based on the plan, one can assess the pros and cons of various migration methods, especially in the context of the analysis done using Vyapin Office 365 migration planning tool, to arrive at an efficient execution plan.