Migrated 80-User Company from Google Workspace + On-Prem File Server to Microsoft 365 (SharePoint as File Server)

Hi everyone,

Just wanted to share a recent migration project we handled for a mid-sized company (~80 users). They were running on a mixed setup:

• Email + Personal Drives: Google Workspace (Gmail + Google Drive)

• File Server: On-prem Windows file server hosting department-wise shares

The client’s pain points were:

• No single platform for collaboration (files in GWS + on-prem server)

• Remote access to file server was clunky (VPN dependent)

• Users using both Google Drive and network drives = confusion

• Management wanted better security, compliance, and remote accessibility

So, the plan was clear: migrate everything into Microsoft 365, make SharePoint Online act as the centralized “file server,” and OneDrive for personal storage.

Migration Steps

1. Assessment & Planning

   • Took inventory of ~2TB file server data (department shares + permissions).

   • Checked Google Workspace storage consumption per user.

   • Designed SharePoint architecture → Department libraries, permissions mapped.

2. Google Workspace Migration

   • Used M365 native migration tool for Gmail, Calendar, Contacts.

   • For Google Drive → migrated to OneDrive for each user.

3. On-Prem File Server Migration

   • Used SharePoint Migration Tool to move department-wise data.

   • Preserved folder structure, permissions carefully mapped.

   • Created libraries for each Department.

4. User Adoption Setup

   • Mapped SharePoint libraries into Windows Explorer (OneDrive sync) → so users still felt like they were working with network drives.

   • Conducted short training: difference between OneDrive (personal) vs SharePoint (team).

Issues Faced (and Fixes)

• Google Drive Personal Files: Some users had personal data mixed in their work Google Drive. Had to filter out what’s business-related.

• File Naming Issues: A few files had unsupported characters (like ?, :) which blocked migration → fixed via pre-check reports.

• Permissions Confusion: Users initially thought OneDrive = “Shared Drive.” Cleared it up with short training sessions.

• Sync Conflicts: Some Excel files caused version conflict errors. Enabled “Always open in desktop app” setting in SharePoint to avoid editing issues.

• User Resistance: A few old-school employees wanted “the same mapped drive” → we had to push the OneDrive sync method so it feels identical.

Outcome

• All 80 users now on M365 → single sign-on, Outlook, Teams, OneDrive, SharePoint.

• File server is decommissioned → no more VPN dependency.

• Management happy with compliance features & reporting.

• Users adapting well after 2–3 weeks of handholding.

Overall, this migration reinforced one thing: user adoption is as important as the technical migration itself. If you don’t train and handhold users, they’ll hate the change no matter how perfect your backend migration is.

Has anyone else here done a similar GWS + on-prem hybrid → M365 SharePoint migration? Curious to hear what tricky issues you ran into.