SharePoint and OneDrive migration: a case study covering the phased file-server retirement, Entra ID identity migration, and adoption work ETTE delivered for a national public-interest law nonprofit.
Retiring a legacy file server, one phase at a time
The client is a national public-interest law nonprofit with attorneys and staff on both coasts. Its files lived on an aging on-premises file server — roughly 2.38 TB across a million-plus files — with years of ad hoc permissions layered on top. Between August 2025 and June 2026, ETTE moved the organization to SharePoint, OneDrive, and Entra ID in two planned phases, timed so a live financial audit was never interrupted and attorneys never had to change how they work mid-case. The client's name is withheld; every date and count comes from the project record.
From aging file server to a cloud-first workplace
ETTE assessed and cleaned up first, mapped every folder to an owner and a destination, then migrated in two phases so the most permission-sensitive data moved only after the process had been proven once.
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Assess and clean up2.38 TB reviewed; oversized archives, stale email files, and media flagged for cleanup or Azure archive before anything moved
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Map the dataEvery folder assigned a destination SharePoint library, an owner, and members — approved by the client before cutover
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Migrate in phasesAdmin and operations data first, legal and legislative second, each over a planned weekend window
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Move identities and devices46 user accounts to Entra ID with MFA confirmed; PC profiles migrated in place, Macs enrolled via Company Portal
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Train and retireAttorney pilot, staff training, and the on-premises file and remote-desktop infrastructure wound down
Two phases, sequenced around who could least afford disruption
Rather than a single cutover, ETTE split the migration in two: administrative and operational data first, legal and legislative data second, so the more complex, permission-sensitive work came after the process had already been proven once. Before anything moved, ETTE's assessment flagged oversized ZIP archives, redundant email archives, and media files for cleanup or Azure archive — shrinking what actually needed to migrate — and years of ad hoc file-server permissions were reviewed and re-mapped to a SharePoint model instead of being carried over and untangled later.
Phase 1 — Admin & Operations
Communications, Finance, HR, Operations, Admin, and Benefits Administration folders migrated over a single weekend, with a defined cutoff and return-to-access window so staff knew exactly what to expect. Permissions were cleaned up and re-mapped before the cutover, not after.
Phase 2 — Legal & Legislative
The legal team's data was more complex and more sensitive, so ETTE ran a small pilot with three attorneys chosen for a mix of easy adoption and high influence, trained them with a slide-based walkthrough, and used their feedback to shape training for the rest of the legal and legislative staff before the full cutover.
Project timeline
Details that mattered more than the technology
Every item below comes from the project record: planning meetings with the client's leadership, the migration ticket history, and the wrap-up correspondence. Dates and counts are taken directly from those sources.
Years of one-off permission grants on the old file server were reviewed and re-mapped to defined SharePoint groups before the Phase 1 cutover, rather than carried over and untangled later. Every library got a named owner and a confirmed member list, approved by the client before the data moved.
The client's accounting and time-tracking systems were migrated with weekend-only downtime windows, backups taken before each cutover, and access re-confirmed with the finance team before Monday morning — all while the organization's annual financial audit was underway.
Rather than training the full legal team cold, ETTE piloted a slide-based walkthrough with a small, deliberately chosen group of attorneys — picked for a mix of receptiveness and influence — and adjusted the material based on their questions before the wider rollout.
ETTE drafted every staff communication about upcoming cutovers, but the client's leadership sent them — a small choice that kept the message trusted internally and made each migration window feel like an organizational decision rather than an IT event.
The ultimate goal is that we equip staff with guidance on how to best leverage our new SharePoint/OneDrive configuration.
— Vice President of Finance, client organization · June 2026, requesting follow-on staff trainingWhere the client stands now
Phase 1 went live in the planned January window; Phase 2 followed the planned mid-May window, each preceded by a confirmed data-mapping and permissions review.
By the May 29 status report, 87% of user migrations were fully complete and closed on Entra ID with MFA confirmed. The six still open were tied to staff leave and scheduling, not technical issues.
Staff work from SharePoint, OneDrive, and Teams. The legacy folder structure that had driven access confusion was formally retired as part of the Phase 2 cutover.
Financial system access was preserved through the concurrent audit period with only planned weekend downtime, as required by the client's leadership.
The pilot-then-rollout training approach meant attorneys had hands-on exposure to SharePoint sync, co-editing, and offline access before their data moved, not after.
In June 2026 the client's leadership asked ETTE for instructor-led training on co-authoring, version history, permission hygiene, and secure guest access for outside counsel — the "teach us to use it better" request a migration is supposed to produce.
The team on the migration
The same core group ran both phases, which meant fewer handoffs and a shared memory of what had already been decided. Descriptions and quoted remarks come from the project's meeting and correspondence record.
Owned the data mapping, permissions cleanup, and both weekend cutovers. Coordinated the accounting and time-tracking system moves around the client's live financial audit so weekday operations were never interrupted, and drafted the leadership-voiced staff communications ahead of each window.
Ran a per-user migration ticket for each of the 46 accounts, confirming Entra ID sign-in and MFA one by one, enrolling Mac users through Company Portal, and tracking follow-ups for staff on leave until every session closed. Reported progress to the client's leadership through go-live week.
The client's finance and operations leadership drove the project from their side: reviewing and approving every data-mapping revision, sending the staff communications ahead of each cutover, flagging the audit and licensing constraints ETTE needed to design around, and requesting the follow-on training that kicked off the adoption phase.
Three attorneys — chosen for a mix of receptiveness and influence within the legal team — piloted the SharePoint training before the wider rollout. Their questions and feedback shaped how the rest of the legal and legislative staff were trained ahead of the Phase 2 cutover.
If your files still live on a server down the hall
File-server retirements for organizations like this one
Nonprofits and professional organizations running on aging file servers face the same tradeoffs this client did: years of accumulated permissions, staff who can't afford downtime, and specialty applications that don't move cleanly. ETTE assesses and cleans up the data first, maps every folder to an owner, migrates in phases sequenced around the business calendar, and stays on for training and adoption through its Microsoft 365 and Cloud, Productivity & Backup practices.
The pattern that worked here — prove the process on operational data first, pilot with the most demanding users before their data moves, and let leadership carry the communication — keeps a migration this size from ever becoming the emergency it's often assumed to be.