27 TB PST Remediation

01Challenge

Outlook PST archives had quietly piled up across SharePoint and OneDrive — more than 27 TB of them in a tenant holding nearly 10 PB of data. PST files are opaque to search, retention, and DLP, so every one was storage the business paid for and content governance couldn't see. And without a control in place, the problem would simply grow back.

02Approach

• Find the real footprint. Identified PST files across SharePoint and OneDrive to measure the true scale of the problem before acting on it.
• Automate the cleanup. Built automated remediation with PowerShell instead of relying on manual, site-by-site removal.
• Stop it coming back. Implemented tenant-level controls so new PST files couldn't accumulate after the cleanup.
• Bring people along. Coordinated enterprise-wide communications and governance changes so users knew what was changing and why.

03Technology

• SharePoint Online
• OneDrive
• PowerShell
• Tenant controls
• Data governance

04Outcome

More than 27 TB of PST data remediated from SharePoint and OneDrive, with tenant controls preventing recurrence and the change communicated across the enterprise. Storage reclaimed — permanently.