windows-resize_partition.ps1

<#
  .SYNOPSIS
    Script resizes a partition, if it has been expanded with 1GB or more - sets to MAX size
  .DESCRIPTION
    Script resizes a partition, if it has been expanded with 1GB or more - sets to MAX size
  .INPUTS
    N/A
  .NOTES
    Author:         Anders Mikkelsen
    Creation Date:  2021-12-23
    GitHub:         https://github.com/amikkelsendk
    Twitter:        @AMikkelsenDK
    
    Tested on:
    - Windows Server 2019

    Requirements:
    Must run with administrative priviliges 

    Credits to:
    https://www.controlup.com/script-library-posts/extend-a-logical-disk-to-maximum-partition-size-for-that-volume/
#>

# Rescan Storage/Disks
Update-HostStorageCache

# Get list of disks
$arrDisks = Get-Disk | Where-object{$_.OperationalStatus -eq "Online" -and $_.PartitionStyle -eq "GPT"}

Foreach ( $objDisk In $arrDisks ) {
  Write-Host "Disk: $($objDisk.Number)"
  $arrPartitions = $objDisk | Get-Partition

  If ( $arrPartitions.Count -eq 1 ) {
    Foreach ( $objPartition In $arrPartitions ) {
      $thisPartitionDriveLetter = $objPartition.DriveLetter
      $thisPartitionDiskSize = $objPartition.Size
        
      #If ( $thisPartitionDriveLetter ) {
      If ( ( $thisPartitionDriveLetter ) -and ( $thisPartitionDriveLetter -ne "C" ) ) {
        Write-Host "  DriveLetter:  $thisPartitionDriveLetter"
        Write-Host "  Current Size: $thisPartitionDiskSize"
        
        $thisPartitionDiskMaxSize = ( Get-PartitionSupportedSize -DriveLetter $thisPartitionDriveLetter ).SizeMax

        # Only if new size is 1GB larger 
        $thisSizeGB    = [math]::Round( $thisPartitionDiskSize/1024/1024/1024, 2 )
        $thisSizeMaxGB = [math]::Round( $thisPartitionDiskMaxSize/1024/1024/1024, 2 )

        If ( $thisSizeGB -lt $thisSizeMaxGB ) {
          # Resize partition to MAX
          Write-Host "  New size:     $thisPartitionDiskMaxSize"
          Resize-Partition -DriveLetter $thisPartitionDriveLetter -Size $thisPartitionDiskMaxSize -Confirm:$false
        }
      }
    }
  }
  Else{
    Write-Host "  !! has 0 or more than 1 partition !!"
  }
}