The 2025 Data Migration Retrospective: What Failed, What Worked, and What We Must Do Differently in 2026

TL;DR

In 2025, enterprise data migrations were bigger and more complex. But there were also clear wins from teams that planned smart and tested early. Organizations are transitioning from on-premises to cloud platforms, such as SharePoint Online. In this blog, we unpack what went wrong, what worked, and share practical content migration best practices and SharePoint migration tips to help you get it right in 2026.

As 2025 draws to a close, enterprise leaders and migration teams are taking stock of a year that saw some of the largest, most ambitious content migration projects to date.

This retrospective breaks down the most common failures, key success patterns, and actionable strategies organizations should carry into 2026. Let’s dive deeper.

What Went Wrong in 2025

Despite new tools and growing experience, some of the same old migration challenges continued to trip up enterprises, just at a much larger scale.

1. Broken Internal Links

When files move, but internal links don’t, users are left with a frustrating experience. Enterprises migrating to SharePoint or Microsoft 365 often forget to adjust links in documents, wikis, and portals. That is why we recommend using the Pre-migration analyzer by Tzunami deployer.

2. Metadata Misfires

Some metadata was lost, and some was often misaligned. Mismatched fields, inconsistent tagging, and failed mapping from legacy ECMs meant content arrived in the new system stripped of its context.

3. Permission Puzzles

Security mapping was another weak point. Permissions from platforms like Documentum, OpenText, or even file shares didn’t cleanly translate to SharePoint structures. In some cases, users lost access altogether; in others, sensitive content became unintentionally exposed.

4. Oversized and Unstructured Repositories

Too many teams migrated everything, including outdated, redundant, or trivial content (ROT). This resulted in bloated SharePoint environments with increased storage costs. They were unaware of Tzunami Archiver[https://staging.tzunami.com/ecm-archiver/], which lets you archive your old data to your file system and migrate only what’s important.

5. Not Enough Testing

Skipping validation was one of the costliest missteps they made. When companies waited until the end to test, they uncovered issues too late, which resulted in rework, delays, or compromised data quality.

📌 If you’re planning a migration in 2026. Start Smarter. Book a free demo here

What Worked (Really) Well

Now, let’s talk about the enterprises that got it right.

1. Phased, Incremental Migrations

Instead of attempting a risky “all-at-once” migration, many of them adopted phased approaches like migrating content in waves, testing as they went, and syncing only the deltas later.

2. Cleanups Before the Move

Smart enterprises didn’t migrate everything. They ran content audits, identified ROT, and made decisions about what should be archived, restructured, or left behind. They used Tzunami archiver to archive their old data.

3. Automation for Metadata and Links

Automated tools that preserved internal links and applied metadata rules at scale saved enormous manual effort. And these capabilities also helped them to maintain consistency across migrated content.

4. Security Mapped Early

Security was built into the migration strategy and not added later. This included carefully mapping users and groups, simulating access rights, and ensuring sensitive data stayed protected throughout the process. A migration tool[tzunami.com] handled it for them.

 5. User-Centric Planning

Involving end users/employees during planning, testing, and validation phases helped reduce post-migration friction. Teams that engaged users to review structure, usability, and access controls built environments that worked from day one, and not six months later.

Content Migration Best Practices for 2026

Want to avoid the mistakes of 2026? Build your 2026 migration around these best practices:

1. Start with a Content Inventory
   Know what you’re moving and why. Categorize content, assess usage, and prioritize what adds real business value.
   
2. Align Metadata Up Front
   Don’t let metadata be an afterthought. Map how legacy fields will translate into your SharePoint or Microsoft 365 environment before exporting anything.
   
3. Validate in Every Phase
   Don’t wait until the test ends. Run validation at each step, like export, transformation, and deployment, to catch issues early.
   
4. Use Purpose-Built Tools
   Scripting can only take you so far. Use migration tools designed for handling ECM-to-SharePoint moves, link preservation, permission mapping, and delta migrations.
   
5. Focus on Adoption
   Migration is just the start. Set up clear governance policies and train users/employees to make the most of your new environment.
   

Final Thoughts

The biggest takeaway from 2025? Migration is no longer just a transformation task. It touches productivity, security, and user experience. Getting it wrong can cause months of disruption. Getting it right sets the stage for long-term success.

Frequently Asked Questions (FAQs)

1. What does the Tzunami Permission Tool do?

It simplifies SharePoint permission management with bulk editing, reports, and user-to-user permission copying.

2. Is it hard to install?

No. It’s an SPFx app you upload once and use across your SharePoint sites.

3. Can I manage permissions in bulk?

Yes. You can select multiple files or folders and update access in one go.

4. Does it replace SharePoint’s built-in tools?

No. It works alongside SharePoint to make permission tasks faster and clearer.

5. What is Tzunami Archiver used for?

It helps you archive old or unused content before migration, so you only move what matters.