What happens if an error is made during an Office 365 migration?

A common scenario for Office 365 users is to move content into the platform from older on-premises versions of Exchange and SharePoint, from file shares or line of business (LOB) applications, or from competing collaborative platforms. Sometimes these moves or migrations are performed with the help of third-party solutions (from independent software vendors, or ISVs), or manually on their own. As part of this migration activity, data can be mislabeled or misplaced, resulting in lost productivity or improper handling of important information assets.

While Microsoft works closely with the ISV partner community to develop fast and flexible tools to help migrate and manage content within the Office 365 platform, these third-party applications are not managed by Office 365 in any way. You can find tools to help you automatically provision new Exchange mailboxes, move public folders regardless of size, and migrate your documents and personal archives while maintaining all metadata and permissions, but as with any other process or tool that requires human interaction, there is room for error during these migration activities.

Unfortunately, sometimes these applications are configured incorrectly or aren’t employed according to the developer’s directions. (It’s almost comical how often cries of “your app deleted all my data” are followed by “the setup guide stated ‘if you do X you’ll overwrite existing data.’”) Office 365 cannot and does not guarantee that the third-party solutions available through the partner ecosystem will be foolproof. Like any software, third-party solutions occasionally have bugs, and even the ones that don’t are often quite easy to misuse. The danger lies in the amount of access these applications have to your Office 365 data.

When you use third-party solutions in conjunction with your Office 365 environment, you grant those applications a specific – and usually quite broad – set of permissions. If an email migration solution can provision and add content to your Office 365 account, it can also delete those accounts – or populate them with the wrong data. The same problems can happen to solutions that support SharePoint Online, OneDrive for Business, or the Office suite of tools.

Why Office 365 can’t stop migration errors

Just as Microsoft can’t tell good commands from bad ones when they come from individual users, Office 365 is blind to correct and incorrect instructions from third-party solutions. For all Office 365 knows, you actually want your migration tools to overwrite all of your existing data and start fresh, or wipe out your extensive taxonomy structure with today’s date as the creation date and “Administrator” as the document creator. Only you know the difference, and odds are you won’t notice an improperly configured solution until after it has inflicted its damage.

What migration errors can cost you

You can sum up what’s at risk with migration errors in one word: Everything. Migration errors are amongst the most dangerous threats to Office 365 data because third-party solutions can touch an entire service or an entire domain.

While most migration solutions handle just part of your overall move to Office 365, all of them can affect enough of your critical business information to do serious damage not just to Office 365, but to your entire business.

How to defend against migration errors

The best defense is to have a plan – which begins with an understanding of what it is you’re planning to move, who owns it, how it should be handled, and where it should all go. The Office 365 community has plenty of information on how to plan for a successful migration to the cloud, and most third-party solution providers will also have ample documentation on running a premigration inventory analysis to help you better understand what you have. Of course, a secure, independent backup of your data is strongly recommended, and will allow you to start over should a malfunctioning third-party solution (or, more likely, a malfunctioning administrator) overwrites, mislabels, or deletes your data.

It should be pointed out that third-party backups are, by definition, third-party solutions – and most of them require the same read/write permissions that make other solutions dangerous. The key to evaluating a good third-party backup and restore application is to ensure it performs non-destructive restores. That’s the technical term for restoring data without overwriting existing data. A good third-party backup solution will restore a backup copy of an Office 365 document alongside an old one, rather than paving over the data in place. If a backup and restore app is limited to non-destructive restores, it can’t harm your existing data.