TL;DR. Private equity firm, 120+ users across three portfolio companies in NAM, EUR, and GBR. Mailboxes, archives, OneDrive, Teams, SharePoint, and workstations migrated simultaneously. Litigation holds preserved, archive size limits resolved, hybrid device ReACL via Ivanti Neurons.
What was the client environment?
A major private equity firm needed to consolidate the Microsoft 365 environments of multiple portfolio companies after a series of acquisitions. The portfolio companies, spanning operations in North America, Europe, and the United Kingdom, each had their own M365 tenants, Active Directory environments, and compliance requirements including litigation holds on archived mailboxes. All needed to be migrated to a unified target platform on overlapping timelines.
What made this migration challenging?
Private equity portfolio migrations are uniquely complex because each company has different IT maturity, compliance posture, and operational requirements, yet they all need to land on the same target platform:
- Simultaneous multi-entity execution. Three portfolio companies needed to be migrated on overlapping timelines, requiring the consultant to context-switch between projects daily while maintaining quality and momentum on each.
- Global user base. Users were spread across NAM (North America), EUR (Europe), and GBR (United Kingdom) regions, with mailbox sync timing and cutover windows needing to accommodate multiple time zones.
- Archive mailbox size limits. Archive mailbox migrations encountered target mailbox size limit errors, requiring analysis and remediation to ensure complete data transfer.
- Litigation hold preservation. One portfolio company had mailboxes under litigation hold, a legal requirement that had to be preserved throughout the migration process. Any loss of litigation hold data could expose the firm to legal liability.
- Hybrid device migration with Entra ID join. On-premises workstations needed to be migrated to the target tenant's Entra ID, requiring ReACL (re-access control list) operations, AD agent deployment via the client's endpoint management tool (Ivanti Neurons), and Entra ID provisioning packages.
- Shared and resource mailbox discovery. Each portfolio company had shared mailboxes and resource mailboxes that needed to be discovered, sized, and migrated alongside user mailboxes.
How did LeadThem approach the migration?
Parallel portfolio execution
Phase 1: Discovery across all entities. Ran mailbox discovery for all portfolio companies including user, shared, and resource mailboxes. Pulled archive mailbox size data and litigation hold lists. Ran DirSync read/match workflows for on-premises users and computers. Updated CDS documentation for each entity.
Phase 2: Data sync and device preparation. Started mailbox and OneDrive initial syncs across all regions, completing GBR and EUR first, then NAM (the largest batch). Ran Teams chat discoveries and SharePoint site analysis. Prepped Entra ID provisioning packages, AD agent installation scripts, and DUA installation scripts for device migration. Configured device migration profiles for ReACL and Entra Join operations.
Phase 3: Production migration and troubleshooting. Executed production migrations per entity while troubleshooting archive mailbox size limit errors. Tested hybrid device ReACL on WhiteStar devices. Managed agent deployment via the client's Ivanti Neurons endpoint tool. Ran delta syncs on mailboxes, OneDrive, and Teams across all entities to minimize cutover window data.
What technical challenges did we solve?
- Archive mailbox migration errors. WhiteStar archive mailbox migrations failed due to target mailbox size limits. Our consultant analyzed the error data, identified which archives exceeded target limits, and provided the client with a detailed report and remediation options, including target mailbox size increases and selective archive migration strategies.
- Litigation hold chain of custody. Mailboxes under litigation hold required special handling to maintain the legal chain of custody throughout migration. Our consultant identified all held mailboxes upfront, documented the hold status, and validated that holds were preserved in the target environment post-migration.
- Multi-timezone sync coordination. With users in NAM, EUR, and GBR, initial mailbox syncs needed to be sequenced to prioritize regions with earlier business hours. Our consultant started with EUR and GBR syncs first, allowing them to complete overnight relative to NAM, then queued NAM syncs, minimizing the total time to achieve a consistent sync state across all regions.
- Device agent deployment at scale. Testing agent deployment via Ivanti Neurons required validation that the customer's endpoint management tool could reliably push Quest AD agents and DUA packages to workstations across all regions. Our consultant tested the deployment chain end-to-end before scaling to production.
- Timeline expansion risk. The addition of a new portfolio company mid-project threatened to require additional hours and potentially delay the existing migrations. Our consultant flagged the risk in RAID updates and worked with the PM to assess timeline impact and secure additional project hours proactively.
What were the results?
All three portfolio companies were migrated to the unified M365 platform, with mailboxes, archive mailboxes, OneDrive data, Teams chats, SharePoint sites, and workstations all transitioned across three continents. Litigation holds were preserved throughout, archive mailbox size issues were resolved, and the private equity firm now has a single M365 platform for centralized IT management across its portfolio.
Which tools and technologies were used?
- Quest On Demand Migration (ODM) for cross-tenant data migration
- Quest ODMDS for directory synchronization and object matching
- Entra ID provisioning packages for device migration
- Device ReACL and Entra Join for hybrid workstation migration
- Ivanti Neurons for remote agent deployment
- Microsoft 365 (Exchange Online, OneDrive, Teams, SharePoint)
- Archive mailbox and litigation hold management
Why LeadThem Consulting
Private equity firms need a migration partner who can manage multiple portfolio companies simultaneously without sacrificing quality on any one engagement. LeadThem Consulting's consultant managed three parallel migrations across three continents, navigating archive size limits, litigation hold requirements, and device migration complexity while maintaining clear RAID tracking and proactive communication. When new portfolio companies were added mid-flight, we absorbed the scope increase and kept all workstreams on track.
