Cross-tenant OneDrive migration with Quest On Demand: a complete step-by-step guide [2025]

Introduction

OneDrive concentrates users’ personal work files, local automations (so-called “Known Folders”/KFM), and a huge portion of the files shared through Teams 1:1 and group chats. In a merger or carve-out, migrating OneDrive across tenants is much more than copying files: you must decide how much version history to carry over, how to reapply permissions, and what to do with sharing links, without breaking day-to-day work.

This guide shares a proven approach with Quest On Demand Migration (ODM): upfront assessment, waves by profile/volume, migration with granular control over versions and permissions, path normalization, and the Desktop Update Agent to point the OneDrive client to the target tenant at cutover.

1. What is Quest On Demand Migration (ODM)

Quest ODM is a SaaS platform for cross-tenant migrations of Microsoft 365 workloads (Exchange, OneDrive, SharePoint, Teams). For OneDrive, ODM provides per-user assessment, batch-based migration, granular version options, permission reapplication, and item-level error reporting. It also integrates with the Desktop Update Agent to reconfigure OneDrive/Outlook/Teams on desktops.

2. Prerequisites, permissions & service limits

Permissions

• Connect source and target tenants in ODM and grant application consents for SharePoint/OneDrive (Graph/SPO APIs).
• Pre-provision OneDrive in the target (assign licenses). Provisioning can take hours to days; do it well before your wave. Use Request-SPOPersonalSite to pre-create personal sites.

Key OneDrive/SharePoint limits

• Max path length: full decoded path (folder path + file name) ≤ 400 characters.
• Max file size: 250 GB per file.
• Sync client: for best performance, keep the total synced items per device below roughly 300,000.
• Large libraries: up to ~30M items, but expect throttling/list view constraints beyond 5,000 items per view.

Validate illegal characters/reserved names (e.g., CON, PRN, disallowed symbols) and ensure support for # and % is enabled if your tenant is legacy.

3. Methodology: waves, staging & comms

Work in waves with a representative pilot (varied areas/volumes). Pre-stage history, run deltas, and keep a tight cutover window. Define KPIs and success criteria with the business, and tailor communications “by role”.

4. ODM preparation: project, discovery & identity matching

Step by step

1. Create the project in ODM and connect tenants (consents).
2. Run Collect OneDrive Statistics to profile volume/health (e.g., long paths, provisioning).
3. Define matching (UPN→UPN or CSV) and pre-provision target OneDrives.
4. Plan waves and windows (pilot → wave 1 → wave 2 → cutover).

Sample CSV (identity matching)

5. OneDrive: versions, permissions & shared links

ODM lets you control how files, versions and permissions migrate, with filters to include/exclude by type, folder or age. At a glance:

Key options in the “OneDrive Migration” task

• File action: skip if the target has an equal/newer version; overwrite if the target is older; or copy on conflict (e.g., suffix _migration_copy).
• Versions: from latest only to a fixed number (2, 5, 10, 30, 60, 90, 365) or all. You can cap version size (e.g., 80 MB).
• Permissions: “do not migrate” or update permissions for migrated content. Note: sharing links aren’t migrated as links; you can convert sharing links to direct permissions in the target.
• Sensitivity labels: optional, if you’ve mapped labels cross-tenant (plan & test).
• Filters: by folder, extension or date (include/exclude).

Good practices

• Provision target OneDrive and allow for propagation.
• Versioning: migrate full history only where it adds value (regulated docs). For “noisy” files (PSTs, DBs, logs) prefer latest version.
• External permissions: if converting links to direct permissions and externals are involved, ensure guests exist in the target or plan a recertification campaign.

6. Names, paths & normalization

OneDrive/SharePoint enforces a 400-character full path limit (path + file name). Reserved names/characters still apply. New UPNs can lengthen URLs, so normalize before moving (folder depth & naming). Include a hygiene step (bulk rename, selective flattening) in your pilot.

7. Throughput, limits & throttling

• Concurrency/control: size waves by actual volume, not just user count. Isolate “whales” (>500 GB or >250k items).
• Sync client: avoid syncing >300k items per device; enable Files On-Demand and exclude dense libraries on Day 0.
• Throttling: respect retry-after; schedule off-peak windows; lean on retries & deltas.

8. Security & compliance (Purview, DLP, labels)

• Purview: map sensitivity labels and retention policies between tenants; validate eDiscovery after each wave.
• External sharing: align SharePoint/OneDrive org-level sharing policy in the target before go-live; enforce Conditional Access for guests.
• Audit: enable audit and review guest access to critical content in the first week.

9. Desktop Update Agent: switching OneDrive on Day 0

Desktop Update Agent (DUA) reconfigures the OneDrive client (and optionally Outlook/Teams) automatically. Deploy via GPO/Intune with your project token and schedule the Switch task for the cutover window. Provide a 1-page validation checklist: cloud icon status, correct account, Known Folders re-linked, sync without errors.

10. Native alternative: Cross-Tenant OneDrive Migration (link redirection)

Microsoft’s native cross-tenant OneDrive migration can, after completion, redirect old sharing links to the new location while the source tenant remains active. This is useful when there are many links in emails, wikis or apps and you want to minimize link recreation. ODM remains preferable when orchestrating multiple workloads with unified templates/reporting.

11. Known Folder Move (KFM) & endpoint readiness (Intune/GPO)

Prepare endpoints to reduce Day-0 tickets:

• Enable Silently sign in users to OneDrive.
• Enable Silently move Windows known folders to OneDrive (Desktop/Documents/Pictures).
• Enforce Files On-Demand and set size thresholds to avoid bulk downloads.

Configure via Microsoft Intune (Settings catalog / Administrative Templates) or GPO if applicable.

12. External sharing & B2B guests during/after cutover

• Review External collaboration settings (Microsoft Entra External ID) and restrict/allow as needed.
• Set SharePoint/OneDrive org-level sharing to the intended level pre-go-live; adjust per-user sites post-migration.
• Require MFA for guests via Conditional Access for sensitive content.

13. Multi-Geo & data residency considerations

If you’re Multi-Geo, treat each geography as a separate instance for migration trusts and mapping, and provide geo-specific URLs everywhere (trusts, mapping files, tooling). Plan queue limits and preferred data locations (PDL) accordingly.

14. Operational checklists (pre, during, post)

Before

• Tenants connected; consents (SPO/Graph) in ODM.
• Identity matching and target OneDrives pre-provisioned.
• Assessment: volumes, long paths, illegal names, external permissions.
• External sharing policy aligned in target.
• Migration template (versions, permissions, filters) validated in pilot.

During

• Monitor batches & remediate item-level errors.
• Run deltas pre-cutover; communicate freeze windows.

After

• DUA (OneDrive switch) and sync validation.
• Recertify critical internal/external access.
• Role-based quick training & week-1 hypercare.

15. KPIs, UAT & acceptance

16. Common risks & mitigations

17. CSVs & helpful snippets

SourceUPN,TargetUPN
ana.perez@source.com,ana.perez@target.com
juan.garcia@source.com,juan.garcia@target.com

# SharePoint Online Management Shell required
Connect-SPOService -Url https://contoso-admin.sharepoint.com
# Pre-provision personal sites for a list of users
Get-Content -Path C:\users.txt | ForEach-Object {
  Request-SPOPersonalSite -UserEmails $_ -NoWait
}

# Illustrative snippet — test before using in production
$repl=@{':']='-';'*'='-';'?']='';'"'='';'<'='('; '>'=')'; '|'='-'}
Get-ChildItem -Recurse | Where-Object { $_.PSIsContainer -eq $false } | ForEach-Object {
  $new = $_.Name
  foreach($k in $repl.Keys){ $new = $new -replace [regex]::Escape($k), $repl[$k] }
  if($new -ne $_.Name){ Rename-Item -LiteralPath $_.FullName -NewName $new }
}

18. Frequently asked questions

19. Official resources

• Quest — On Demand Migration (User Guide)
• Quest — Desktop Update Agent (User Guide)
• Microsoft — Pre-provision OneDrive
• Microsoft — OneDrive/SharePoint restrictions & limits
• Microsoft — SharePoint Online limits (incl. 250 GB file size)
• Microsoft — Cross-Tenant OneDrive Migration (overview)
• Microsoft — Cross-Tenant OneDrive Migration (FAQs)
• Microsoft — Redirect/move Known Folders to OneDrive
• Microsoft — Use OneDrive policies (GPO/Intune)
• Microsoft — Configure external collaboration (B2B)
• Microsoft — Manage external sharing (SharePoint/OneDrive)
• Microsoft — Microsoft 365 Multi-Geo

20. Conclusion & next steps

A successful cross-tenant OneDrive migration blends: solid assessment, path normalization, clear decisions about versions, permissions and links, wave-based execution, and DUA on desktops. ODM adds control, reporting and consistency when migrating several workloads in parallel.