Get Preservation Library

This PnP PowerShell script checks whether a Preservation Hold Library exists on a SharePoint site and reports how many items it contains. The Preservation Hold Library is created automatically when a Microsoft Purview retention policy is applied to a site and is not visible to standard users, but counts toward the site's storage quota.

Purpose

Use this script to:

• Confirm whether a retention policy has triggered a Preservation Hold Library on a site
• Get an item count as an indicator of retention activity on the site
• Support storage investigations where high consumption cannot be explained by visible content
• Identify sites with active compliance holds before running version trimming operations

Prerequisites

• PnP PowerShell module installed
• SharePoint Online Admin permissions or Site Collection Administrator rights
• An Azure AD app registration with a client ID (for -ClientId authentication)

$clientId = ""
Connect-PnPOnline -Url "https://tenantName.sharepoint.com/sites/siteName" -ClientId $clientId -Interactive
$list = Get-PnPList -Identity "Preservation Hold Library" -ErrorAction SilentlyContinue
if ($list) {
    $items = Get-PnPListItem -List "Preservation Hold Library" -PageSize 500
    Write-Host "Preservation Hold Library found. Item count: $($items.Count)"
} else {
    Write-Host "No Preservation Hold Library found on this site"
}