OneDrive Admin Checklist: file server migration misses files for executive data

When migrating files from a file server to OneDrive, some files may not transfer. This problem often affects executive data such as sensitive documents, compressed archives, and files with long paths or special characters. The issue occurs because OneDrive Sync has known limitations with certain file types, path lengths, and folder structures that file servers do not enforce. This article provides a checklist to identify and resolve missing files during migration, with specific attention to executive data.

Why File Server Migration Misses Executive Data in OneDrive

File servers allow folder structures and file names that OneDrive does not support. OneDrive Sync enforces a maximum path length of 400 characters. File names cannot contain characters like " : < > ? \ |. File types such as .pst, .ost, .tmp, and .lnk are blocked by default. Executive data often includes password-protected archives, Outlook data files, and deeply nested folders that exceed these limits.

Additionally, OneDrive Sync does not sync files with the following attributes: hidden, system, or encrypted with EFS. File server permissions may prevent the migration tool from reading certain folders. The migration tool itself may skip files that are open or locked by another process. These conditions cause missing files that are not reported as errors.

Pre-Migration Checklist: Prepare Executive Data for OneDrive

1. Audit file paths and names
   Use PowerShell script Get-ChildItem -Path \\fileserver\share -Recurse | Where-Object { $_.FullName.Length -gt 400 } to list files with paths longer than 400 characters. Rename or move these files to shorter paths.
2. Remove blocked characters from file names
   Scan for characters " : < > ? \ | using a tool like PowerShell Replace. Replace each character with an underscore or hyphen.
3. Identify and convert blocked file types
   Locate .pst, .ost, .tmp, .lnk, .url, .deskthemepack, and .exe files. Move .pst files to a local archive or convert them to Outlook.com format. Remove shortcut files.
4. Remove hidden and system attributes
   Run Get-ChildItem -Recurse | Where-Object { $_.Attributes -match 'Hidden' -or $_.Attributes -match 'System' } | Set-ItemProperty -Name Attributes -Value 'Normal' to clear these attributes.
5. Decrypt EFS-encrypted files
   Use cipher /d /s:C:\sourcefolder to decrypt files before migration. OneDrive does not support EFS encryption.
6. Close all open files
   Ensure no user has executive files open. Use OpenFiles command on the file server to check for open handles.

Post-Migration Verification: Check for Missing Executive Data

1. Compare file counts between source and destination
   Use PowerShell (Get-ChildItem -Path \\fileserver\share -Recurse -File).Count on the source and (Get-ChildItem -Path $env:OneDriveConsumer\ -Recurse -File).Count on the local OneDrive folder. A mismatch indicates missing files.
2. Review OneDrive Sync status
   Open OneDrive Settings > Sync and backup > Manage backup. Check for any files that show a red X or a sync error icon. Click the OneDrive icon in the system tray and select View sync problems.
3. Check OneDrive Recycle Bin
   Go to the OneDrive web interface > Recycle bin. Files deleted during migration may appear here. Restore any executive files that were accidentally removed.
4. Use selective sync to verify folder presence
   In OneDrive Settings > Account > Choose folders, confirm that executive folders are checked. If a folder is missing from the list, it did not sync.
5. Run a third-party migration report
   If using a migration tool like Sharegate or Mover, generate a detailed report that lists each file and its transfer status. Look for rows with status Skipped or Failed.

If Executive Files Are Still Missing After Migration

OneDrive does not sync files with long paths

Files with paths longer than 400 characters are silently skipped. Move these files to a shallower folder structure on the file server and re-run the migration. Alternatively, use the OneDrive web interface to upload these files directly, which accepts paths up to 400 characters.

Password-protected archives are blocked

OneDrive cannot scan or sync password-protected ZIP, RAR, or 7z files. Remove password protection before migration. If the archive must remain protected, store it in a separate SharePoint document library and grant access only to specific users.

Files with special characters in the name fail to upload

Characters like # % & { } ~ can cause upload failures. Use PowerShell to rename files: Get-ChildItem -Recurse | Rename-Item -NewName { $_.Name -replace '[#%&{}~]', '_' }.

File server permissions prevent reading

The migration tool runs under a service account that may not have read access to executive folders. Grant the service account Full Control on the source folders, or use an account that is a member of the local Administrators group on the file server.

OneDrive Sync app is not running or signed in

If the OneDrive Sync app is paused or signed out, files will not upload. Check the system tray for the OneDrive icon. If it has a red X, click it and select Sign in. Ensure the app is running: press Ctrl+Alt+Delete, open Task Manager, and verify OneDrive.exe is listed under Processes.

Item	File Server	OneDrive
Maximum path length	32,767 characters	400 characters
Allowed file name characters	Almost all Unicode except \ / : ? " < > |	Same restrictions plus blocked characters # % & { } ~
Blocked file types	None by default	.pst, .ost, .tmp, .lnk, .url, .exe, .deskthemepack, and others
EFS encryption	Supported	Not supported; files are skipped
Hidden and system files	Visible on server	Not synced by default
Open or locked files	Can be read by backup tools	Cannot be read if open by another process

After completing this checklist, you can confirm that all executive data has been migrated. Run a final comparison using the file count method described above. For future migrations, enable Known Folder Move to redirect executive Documents, Desktop, and Pictures folders to OneDrive. As an advanced tip, use the OneDrive Admin Center Reports > Storage to view storage consumption per user and spot any missing folders that have zero bytes.