Let’s assume you’ve decided to pursue an Exchange Online migration. Perhaps you simply just want to take advantage of all the benefits that moving your mailboxes to the cloud can provide to your organization and your end-users?

What should you avoid in an Exchange Online migration?

Let’s dive into what you shouldn’t be doing when planning your Migration On Premise Exchange Mailboxes to Office 365 project.

1. Don’t move everything

Many administrators and leadership assume that users want and need every bit of their data to effectively function in their daily work lives and without it there would be a revolt. Experts we spoke to unanimously agree moving all your data upfront isn’t always attainable or required. Based on decades of experience designing, deploying, and managing migration projects, I wholly agree.
Now the primary focus of this blog is to discuss moving mailboxes from on-premises Exchange to the cloud. All the Exchange gurus out there right now reading this are uttering this phrase, “You can’t filter mailbox content using Mailbox Replication Service (MRS)”. And, of course, they are right, you can’t filter using this migration method. BUT… who is to say you must use this method if it doesn’t meet your project requirements? You don’t want to bend your project requirements to the tools you are using, instead find the correct tools that fit your requirements. There are plenty of reliable solutions on the market to copy mailbox data that provides filtering options.
For the sake of this discussion, let’s move beyond Exchange Online mailboxes and expand our topic to include other potential migration workloads that you may encounter during an Exchange Online migration project.
When moving users up to the cloud, they have mailboxes, archives, files, and Public Folders. When you move between tenants, you add to the user’s workloads, private, group and meeting chats, and to the shared workloads you also add SharePoint, Teams and Groups. All these different workloads are unique to each identity and can amount to terabytes or petabytes of data. A vast majority of this data is historical, rarely accessed and more than likely not required within the next 90 days. That 90 days provides you a window of opportunity to accelerate your migration velocity and meet those difficult timelines.
When you have a lot of data to move and a short time to move it, our experts recommend the following strategy to meet your migration goals.
Provide the last 90 days of used data to each user then backfill their historical data after the user has been moved.
Once the user is moved and working in their new environment, you’ll have time to migrate all their historical data while they continue to manage their daily workload.
By reducing your initial data footprint, it becomes possible to move your users to the target more quickly.
Here is a surefire set of parameters to meet your user’s needs while keeping the initial data size as small as possible.
Migrate the last 90 days of mail, the next 90 days of meetings with all reoccurring meetings, all personal contacts, and tasks. Those parameters cover your user’s mailbox content.
Migrate the most recently used files and folders by age, keep file versioning to a minimum by only migrating the latest versions and filter out files that are too large or perhaps common file types like media files that tend to be larger.
I’m not going to cover the other workloads because these tips should get your mailboxes to Exchange Online as quickly as possible. However, the strategy is the same for the other workloads. Reduce the initial data move to migrate your users over to the target as quickly as possible then backfill their historical data.
As organizations expand their cloud storage usage, there may come a time when migrating ALL your cloud data up-front is no longer practical. Adopting this type of strategy will be important to successfully move the vast volumes of data stored in today’s modern workloads. The lesson to take away from all of this is, if you want to crunch a lot of data into a rapid timeframe, reduce the upfront load by using age filters, cutover your users and then backfill historical data over time. You’ll find your users remain productive and most are unaware that some data may not be there yet, because all their most recent work is.

1. Don’t overburden your support staff When planning a phased Exchange Online migration project, our experts recommend that you size each migration event (i.e. how many objects), based on the amount of data you can push and the amount of change your organization can absorb during that event. In this blog, we are focused on the organizational impacts a migration can have, regardless of how prepared you are. We recommend that you ramp up to find terminal velocity. You will know when you have exceeded your support organizations and migrations teams’ capacity to maintain terminal velocity when your team is still managing migration tasks and/or remediation issues that were expected to have been completed hours before and you are running into the next event’s scheduled activities. If you have two consecutive events like this, revaluate your capacity and adjust.

Scheduling
The experts overwhelmingly recommended that you schedule migration tasks on the weekdays to begin to push data into the target. Optimally, scheduling during off-peak hours is the best practice to maximize data throughput but we also always recommend that data be migrated continuously, just to a lesser extent. Smaller batches during the day, with larger ones during off-peak times.
Schedule the final events that impact the end-users during the start of a weekend so that final delta migrations and related post-migration activities may complete while the end-user’s applications are reconfigured. On Monday, when the end-users return to work, their latest data will be available for them to begin their workweek. However, there will be problems, confusion, and general questions… there always is. This is when internal and any augmented support staff will begin to receive the first influx of new incidents for users.

Communication
If you read part two of this blog series: 5 tips for planning an Exchange Online migration, I spoke about the importance of over-communicating to your end-users and providing great resources in the form of documentation and videos. If planned properly, your support staff will have answers to frequently asked questions and have resolutions on-hand to the most common connection issues, like new passwords and logins. We recommend involving your support teams in pilot events and providing them an easy conduit to access logs, Microsoft O365 Migration statuses and reports so they are totally prepared to process as many incidents that reach them to ensure you reach your terminal velocity.

Event design
The final piece of wisdom the experts shared about optimizing the size of your migration events was that not all events must be equal. Don’t think because you prove your organization can manage moving 2,000 users over a weekend that the following weekend you must do the same. The goal is to reach the final number. If one week you can maximize velocity with 2,000 users, do it! However, if the next weekend, it is a different region or office, which only hosts 500 users, don’t get locked into a single size. Design the scheduled events based on the known local factors, such as the end-user’s location, time zones, connectivity limitations, support availability, etc. All support is local, so be sure your events are based on local conditions, not just how much data you can migrate at a time. That is only one variable in capacity planning for a migration project.

1. Don’t migrate to Azure Active Directory… yet!

If you are moving your mailboxes to Exchange Online, and maybe even some of those legacy commercial off-the-shelf software products you have, you may feel the urge to start investigating if you should migrate services that on-premises Active Directory (AD) provides today to Azure Active Directory. Our experts say don’t waste your time. This isn’t the time to consider that type of move. However, if you do in the future decide that moving identity management to Azure exclusively is the right move for your organization, then moving your user’s data like mailboxes and Public Folders would be a prerequisite to begin the process. The path you are on—getting that remaining user data into the cloud gets you one step closer to retiring additional Microsoft infrastructure from on-premises data centers, reducing ownership costs and expanding your organization’s capabilities and options for the future.

To learn about Process to Move from Google Drive to OneDrive visit O365CloudExperts.