SharePoint Migration Elevated: Migration Manager Over SPMT

The Point

If you still run your SharePoint migrations with the SharePoint Migration Tool (SPMT), Migration Manager is the upgrade worth switching to — same job, far less babysitting.

Context

SPMT got the job done for years, but it has a ceiling. It runs on a single machine, you drive each migration from that one desktop, and the reporting lives wherever the tool happens to be installed. Point it at a few large shares and you’re either funnelling everything through one box or installing the tool on several machines and tracking them all by hand.

Migration Manager — built straight into the SharePoint Admin Center — does the same file-share-to-Microsoft-365 job, only it’s the version that doesn’t make you babysit it. Here’s what actually changed.

You scale with agents, not with patience

This is the big one. Instead of one machine doing the copying, you install a lightweight agent on as many servers or VMs as you like. Each agent runs as a Windows service and authenticates to both your on-prem source and your Microsoft 365 destination. Tasks get handed automatically to the next available agent in the group.

With SPMT, more data meant more waiting on a single machine. With Migration Manager, more data just means more agents. Tight cutover window on a big fileserver? Stand up a few agents and run the uploads in parallel.

Prescan catches problems before you start

Migration Manager scans your file shares first and surfaces the errors and issues up front — long paths, unsupported characters, blocked file types, oversized items. You see the trouble before a single byte moves, instead of finding it in a failed-items report afterwards.

That pairs neatly with selective migration: the prescan shows you which folders came back clean, so you migrate those and circle back to fix the flagged ones separately. No all-or-nothing gamble on a messy share.

One console for monitoring and reporting

Every agent reports into the same console, so you get progress across all agents, downloadable summaries of each migration job, and detailed per-migration data in one place. When someone asks whether the Finance share is done, you have an answer instead of an RDP session into a copy job — the part that felt genuinely tedious on SPMT.

Two ways to handle incremental runs

For staged cutovers you usually want a final catch-up pass, and you get two options:

• Delta sync — moves only the items that are new or changed since the last run, skipping anything already migrated. Faster, because it doesn’t re-examine the whole tree.
• Full incremental — compares all source items against the destination and moves anything new or changed. Slower, but thorough when you want certainty that source and destination truly match.

Use delta sync for speed during the staged phase, then a full incremental on the final pass when you want to be sure nothing slipped through.

Before you start

A few things to have in place first:

• Destination access — Global admin, or SharePoint/OneDrive admin, on the target tenant.
• Source access — Windows credentials with read access to the file shares you’re migrating.
• SMB 2.0 or higher — the server hosting the source data has to support it.
• Open endpoints — make sure each agent machine can reach the required Microsoft 365 endpoints.
• File size — files up to 250 GB are supported.

Takeaway

SPMT isn’t broken, but it’s built for one machine and one operator. Migration Manager keeps the same migration engine and wraps it in central management, parallel agents, and reporting you can actually share. If you’re already in Microsoft 365, the better tool is sitting in the admin center — and it costs nothing extra.

References

• Migrate your file shares to Microsoft 365 with Migration Manager — Microsoft Learn