Automating Cleanup of Orphaned OneDrive Sites using PnP PowerShell

Orphaned OneDrive for Business sites are created when an employee leaves an organization, and their OneDrive account remains active without an owner. These orphaned sites consume storage and may pose security risks if not managed properly.

With PnP PowerShell, you can automate the detection and cleanup of orphaned OneDrive sites by:
✔ Identifying sites without an active owner
✔ Notifying administrators for review
✔ Deleting orphaned sites automatically

Step 1: Install & Update PnP PowerShell

Before running any script, ensure PnP PowerShell is installed. Open PowerShell as Administrator and run:

Install-Module -Name PnP.PowerShell -Force -AllowClobber

To update:

Update-Module -Name PnP.PowerShell

Step 2: Connect to SharePoint Admin Center

Since OneDrive for Business is part of SharePoint Online, connect to the SharePoint Admin Center:

$adminUrl = "https://yourtenant-admin.sharepoint.com"
Connect-PnPOnline -Url $adminUrl -Scopes "Sites.FullControl.All" -Interactive

For app-based authentication:

$clientId = "your-client-id"
$tenantId = "your-tenant-id"
$clientSecret = "your-client-secret"

Connect-PnPOnline -Url $adminUrl -ClientId $clientId -ClientSecret $clientSecret -Tenant $tenantId

Step 3: Retrieve All OneDrive Sites

To list all OneDrive sites in your tenant:

$oneDriveSites = Get-PnPTenantSite -IncludeOneDriveSites | Where-Object { $_.Url -like "*-my.sharepoint.com/personal/*" }
$oneDriveSites

Step 4: Identify Orphaned OneDrive Sites

Find OneDrive Sites Without Owners

To identify orphaned OneDrive sites, check if the SiteOwner field is empty:

$orphanedSites = @()

foreach ($site in $oneDriveSites) {
    if (-not $site.Owner) {  
        $orphanedSites += [PSCustomObject]@{
            OneDriveSite = $site.Url
            LastActivity = $site.LastContentModifiedDate
        }
    }
}

$orphanedSites | Format-Table -AutoSize

Step 5: Export Orphaned Sites Report

To export orphaned sites to a CSV report for manual review:

$reportPath = "C:\Reports\Orphaned_OneDrive_Sites.csv"
$orphanedSites | Export-Csv -Path $reportPath -NoTypeInformation
Write-Host "Orphaned OneDrive sites report exported to $reportPath"

Step 6: Notify Admins About Orphaned Sites

To send an email to IT admins for reviewing orphaned sites, use the Microsoft Graph API:

$adminEmail = "admin@yourdomain.com"
$subject = "Orphaned OneDrive Sites Report"
$body = "Please review the attached report of orphaned OneDrive sites."

Send-MailMessage -To $adminEmail -From "noreply@yourdomain.com" -Subject $subject -Body $body -Attachments $reportPath -SmtpServer "smtp.office365.com" -UseSsl -Port 587 -Credential (Get-Credential)

Step 7: Automatically Delete Orphaned OneDrive Sites

Once orphaned sites are identified, they can be deleted automatically:

foreach ($site in $orphanedSites) {
    Write-Host "Deleting orphaned OneDrive site: $($site.OneDriveSite)"
    Remove-PnPTenantSite -Url $site.OneDriveSite -Force
}

Step 8: Automate the Cleanup Process

1. Open Task Scheduler

Click Start, search for Task Scheduler, and open it.
Click Create Basic Task.
Name it “Orphaned OneDrive Cleanup”.

2. Set Trigger

Choose Weekly or another frequency.
Set execution time.

3. Set Action

Select Start a Program.
In Program/Script, enter: powershell.exe
In Arguments, enter: -File "C:\Scripts\OrphanedOneDriveCleanup.ps1"
Click Finish.

This will detect and delete orphaned OneDrive sites automatically.

Step 9: Monitor & Validate Cleanup

To manually check if the orphaned OneDrive sites were deleted, run:

Get-PnPTenantSite -IncludeOneDriveSites | Where-Object { $_.Url -like "*-my.sharepoint.com/personal/*" }

✔ Ensures only active sites remain
✔ Confirms successful cleanup