By David Todd 

IT Naturally was given the challenge to migrate one Microsoft Office 365 tenant with over 2,200 users to a new O365 tenant, and it wasn’t just the email users that were in scope, but also shared mailboxes, OneDrive, Microsoft Teams and SharePoint sites. To give it that extra twist of complexity, this wasn’t a cloud only migration. Users have on-prem Active Directory accounts which are synced using Azure AD Connect, so we also had to synchronise users to a new on-prem Active Directory forest and sync that to the new tenant, then the sync of the O365 data could take place. There were a lot of moving parts! 

The customer’s timeline was short and fixed due to business requirements: project initiation to completion was about 6 weeks. As you’d expect of any large and responsible company, the customer also needed us to undertake this with minimal impact to the business users. 

To deliver this we used software from Binary Tree 

  • Directory Sync Pro was used for the Active Directory forest sync, copying across users (with their passwords), contacts and groups.  
  • Power365 was used for the O365 tenant-to-tenant migration, including email, OneDrive and Teams.  

Using these tools, we were able to keep the customer’s primary mail domain available throughout the migration weekend, and even able to have users send mail from their normal email address regardless of whether they’d already been migrated or not. Everything was completed over the weekend, starting on the Friday evening and finishing Sunday night, albeit with some very long hours worked! 

Some of the key things to look out for when planning an O365 migration are: 

  • Prepare as much as possible: go through all the types of users and their particular use cases; really understand your current estate, as that’s going to help you massively in the new one. 
  • Secure your new tenant in advance and make sure the implementation is signed off by the Security Team. 
  • Run PoCs and pilots for as many scenarios as possible. 
  • Create a rigorous implementation runbook that everyone involved has access to. Make sure that everyone is fully engaged in its creation and understands it as well as the people who are implementing it.
  • Provide as much communication to the users as possible, and make sure to spend enough time creating some FAQs. When will it happen? What will change? What do I need to do? What will be different? What if I need it in blue? What if I only work every third Tuesday?
  • Know that regardless of how well prepared you are there will always be a few quirks you didn’t expect, or users come out of the woodwork with unexcepted requests. That’s fine, just be ready to react.
  • IT Naturally changes all are run by our 24x7x365 Service Desk: they’re the front line and will be the first to hear the good, the bad and the ugly. They will keep the runbook up to date and ensure that we’re on track, prompting the implementers and testers for feedback throughout.
  • Finally, it’s crucial to have a great working relationship with the company whose services are affected. IT Naturally ran this project, but it was very much a team effort with the customer, which really helped it be so successful.  

If you are looking to complete a Tenant to Tenant Migration, IT Naturally can help. If you would like to discuss how, please call us on 0208 016 2126 or enquiries@ITNaturally.com 

“We were able to keep the customer’s primary mail domain available throughout the migration weekend, and even able to have users send mail from their normal email address regardless of whether they’d already been migrated or not.