Retiring a 9 TB File Server at an 850-Person Architecture Firm
Northline Architects has 850 staff. Project data - about 9 TB of DWG, PDF and Revit files, roughly 600 GB per project across 14 active project teams - sits on a 2012 file server whose warranty ends in one quarter. Staff already use OneDrive for personal documents and report sync clients stuck at '1 of 40,000 files'. Leadership wants the file server retired this quarter, wants 'everything in Teams', and wants the on-premises tape backups cancelled to save cost. About 60 external consultants need access to three projects each. The tenant has 850 Microsoft 365 E3 licences.
1. Where should the 9 TB live, and what does 'put it in Teams' actually mean architecturally?
Read the worked answer
Correct the mental model first: Teams does not store files. Every file posted in a channel lands in a SharePoint document library behind that team, and every file shared in a one-to-one chat lands in the sender's OneDrive. So 'everything in Teams' is really a SharePoint information-architecture decision wearing a Teams interface.
Recommended shape:
- One SharePoint site per project, with a Teams team attached as the front end for the project team. Project number lives in the site name and in managed metadata so it is findable years later.
- Never OneDrive for project data. OneDrive is tied to a person; when the architect leaves, the 600 GB of project files become an offboarding problem rather than a project asset.
- Kill the sync problem, do not migrate it. 600 GB synced in full to every laptop is what produced '1 of 40,000'. Use Files On-Demand and sync only the library folders a person is actively working in.
- Check pooled storage against the current per-licence formula for 850 E3 seats; 9 TB should fit, but confirm before committing to a retirement date, and set a per-site quota so one project cannot consume the pool.
2. Should the on-premises tape backups be cancelled once the data is in SharePoint?
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No - and this is a classic false economy.
SharePoint gives you high availability, geo-redundancy and recycle bins (site and site-collection level). Those protect against hardware failure and against a user deleting a file last week. They do not give you a recovery point you control against the two scenarios that actually kill architecture firms:
- Mass deletion or ransomware encrypting or wiping libraries faster than the recycle bins and versioning limits can absorb, with the recycle window expiring before anyone notices.
- Regulatory or contractual recovery-point requirements - 'restore the project to how it looked on 14 March' is a backup question, not a recycle-bin question.
Two controls, used together:
- Retention labels and versioning to preserve content against deletion and to set a defensible retention period per project type.
- A real backup of Microsoft 365 - third-party SaaS backup, or keep a controlled on-premises copy - before the tapes are retired.
The cost of one backup service for 9 TB is trivial against re-surveying a building or defending a professional-negligence claim. Cancel the tapes only on the day the replacement is proven by a test restore.
3. How should the 60 external consultants be given access to three projects each?
Read the worked answer
Use identity-based external sharing, not link-based sharing, and scope it per project.
- Entra B2B guest accounts, invited per consultant and added to the three relevant project sites (or to the corresponding Teams team as a guest). Guest access is per-resource, so a consultant on projects A, B and C sees nothing of D through N.
- Turn off anonymous links at tenant level, or at minimum on the project sites, and set the default sharing link to specific-people with an expiry. A 'anyone with the link' URL on a 600 GB project library is an unmanageable leak channel and usually breaches the client contract.
- Sensitivity labels on project libraries so that a labelled document keeps its protection if a consultant downloads it.
- Lifecycle: access reviews on the guest population each quarter, with automatic removal at contract end. Sixty consultants times three projects is a matrix that decays quickly once someone's engagement finishes.
Guardrail to state to leadership: sharing outside the tenant is per-site, so one misconfigured project site does not open the other thirteen.