Pre-Migration Scanning

Analyze your files for SharePoint compatibility issues before migrating.

Pre-Migration Scanning

Scanning analyzes your source files to identify potential issues that could cause migration failures. Running a scan before migration is required - this ensures you can address problems before they affect your migration.

Why Scan First?

SharePoint has specific requirements for file names, paths, and file types. Issues that seem minor on a local file system can cause:

  • Silent migration failures
  • Broken files in SharePoint
  • Incomplete folder structures
  • Wasted time and bandwidth

A pre-migration scan identifies these issues so you can fix them beforehand.

Issue Types

Path Length

SharePoint has a 400 character limit for the full path including the site URL. Files exceeding this limit will fail to upload.

Example:

https://contoso.sharepoint.com/sites/Marketing/Shared Documents/Projects/2024/Q4/Campaign Materials/Final Versions/Approved/...
The scan shows the SharePoint path length, not the local path length. Your destination choice affects which files are flagged.

Invalid Characters

SharePoint doesn't allow these characters in file or folder names:

CharacterName
"Double quote
*Asterisk
:Colon
<Less than
>Greater than
?Question mark
/Forward slash
\Backslash
|Pipe

Files with these characters need to be renamed before migration.

Reserved Names

Windows and SharePoint reserve certain file names:

  • CON, PRN, AUX, NUL
  • COM1 through COM9
  • LPT1 through LPT9
  • _vti_ prefix (SharePoint internal)
  • .lock, desktop.ini, thumbs.db

Blocked Extensions

SharePoint blocks certain file types for security:

  • Executables: .exe, .dll, .bat, .cmd
  • Scripts: .ps1, .vbs, .js (as attachments)
  • System files: .sys, .inf
The full list is managed by your SharePoint administrator and can be customized in the SharePoint admin center.

File Size

SharePoint Online supports files up to 250 GB. Files exceeding this limit cannot be uploaded.

Reading Scan Results

After a scan completes, you'll see:

Health Bar

The health bar shows your migration readiness at a glance:

  • Green (Ready): 95%+ files have no issues
  • Yellow (Review): 80-95% files have no issues
  • Red (Issues): Less than 80% files have no issues

Issue Breakdown

The issue breakdown shows how many files are affected by each issue type, with a bar chart for visual comparison.

Issue Details

Click View Issues to see a detailed list of every file with issues. You can:

  • Search for specific files or folders
  • Filter by issue type
  • Export to CSV for offline analysis or sharing with clients

Addressing Issues

Before Migration

For critical issues (path length, invalid characters):

  1. Export the issues list to CSV
  2. Share with the client or fix files directly
  3. Re-run the scan to verify fixes

During Migration

Some issues are handled automatically:

  • Path length warnings: Files will be attempted but may fail
  • Blocked extensions: Files are skipped (logged as errors)

Re-Running Scans

You can run multiple scans on the same project. Each scan:

  • Replaces the previous scan results
  • Shows fresh issue counts
  • Uses the current destination for path length calculations

This is useful after fixing issues or changing the destination.