by: VMware UCC Architect Boney Francis
Migrating applications to a cloud SaaS environment such as Office 365 (O365) is not for the faint-hearted as there are many pitfalls along the way. The key is to ensure the three pillars of any migration—people, process, and technology—are fully accounted for and treated with due diligence. Rigorous preparation is the most mission-critical aspect to get correct as it will dramatically reduce any challenges with the actual migration.
The following is an overview of how VMware IT successfully migrated its legacy systems to O365, including the lessons we learned along the way.
Phase 1: Discovery and Understanding the Environment
Identify all the resources, including all relevant stakeholders.
- Prepare a detailed inventory of the existing infrastructure. Microsoft tools such as OnRamp, IDFix, Deployment Assistant, MAP toolkit, MOSDAL, and others can be invaluable.
- Create a detailed architectural diagram of the current email environment, with special emphasis on mail flow, client connectivity and device authentication flows/methods.
- After completing the above, itemize the pros and cons so that every stakeholder agrees to acceptable risks. This will help alleviate last minute setbacks. The list should be fluid, and should be re-evaluated on a regular basis.
- Finalize the integration and migration approaches, along with timelines for each phase.
Phase 2: Prepping the Source and Resources
This phase includes upgrading the current infrastructure (Active Directory, Exchange, clients, applications, network, etc.) to support the new platform. Collaboration/commitment from different teams across regions is required, and this could take months depending on changes needed.
What to consider at this phase:
- Re-run the inventory and discovery tools after each milestone to guarantee all required upgrades/changes have passed.
- Ensure all support teams (first-level, second-level, third-level, escalations, engineering, etc.) receive appropriate training to effectively address all post-migration issues.
- Determine what O365 monitoring tools will be used.
While this phase may seem easy in comparison to phase 1, it took VMware IT more than four months to complete.
Phase 3: Migration Schedules and Timelines
Setbacks in Phase 3 (the actual migration) can be avoided if Phase 1 and 2 activities are smoothly executed. Here are the best practices for this phase:
- Understand the migration impact for each business unit and schedule a phased-migration approach per unit.
- Prepare an inventory of number of users and mailbox sizes of each scheduled migration batch.
- Communication is vital. Keep the users apprised on their mailbox migration schedules.
- Define a minimum time for pre-stage migration batches, depending on the network throughput between on-premises and O365.
- We found upgrading to a dedicated 10 Mbps circuit increased throughput from 6 to 8 GB per hour to 60 to 80 GB per hour.
- Be prepared for unforeseen impacts during the first few migration waves, and always keep support teams in the loop.
- Ensuring that migrating mailboxes are in licensing compliance can be tricky. To avoid pitfalls, our in-house experts developed a PowerShell script to automatically license the mailboxes post migration.
Lessons from the Migration Team
Here are some words to the wise to make your migration as hassle-free as possible:
- Set expectations as it you may encounter a few delays to complete mailbox provisioning, during which O365-based mailboxes will not be available.
- Occasionally a migrated account may show up as mail user (instead of a mailbox). The PowerShell script should eliminate this issue.
- On very rare occasions, the final cleanup of source mailboxes does not complete. Be aware that this leaves the on-premises and O365 mailboxes both active.
- Avoid having a password expire in the middle of the migration period by using a service account instead of an administrator password.
- A dedicated circuit is recommended to avoid unrelated projects/activities from affecting bandwidth throughput.
Once the migration is completed, celebrate with the stakeholders!
A successful migration process requires coordinating three pillars of IT: the people, process, and technology. Careful preparation will help reduce the number and severity of the issues encountered during the actual migration.
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