DSC_Disk: Add dev drive creation support to disk resource

CHANGELOG.md

@@ -5,6 +5,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Updated DSC_Disk to allow volumes to be formatted as Dev Drives:  Fixes #276
+
 ## [5.1.0] - 2023-02-22
 
 ### Changed

source/DSCResources/DSC_Disk/DSC_Disk.psm1

@@ -173,6 +173,12 @@ function Get-TargetResource
     .PARAMETER ClearDisk
         Specifies if the disks partition schema should be removed entirely, even if data and OEM
         partitions are present. Only possible with AllowDestructive enabled.
+
+    .PARAMETER DevDrive
+        Specifies if the volume should be formatted as a Dev Drive.
+
+    .PARAMETER UseUnallocatedSpace
+        Specifies that a new partition and volume should be formatted onto unallocated space on the disk.
 #>
 function Set-TargetResource
 {
@@ -222,7 +228,15 @@ function Set-TargetResource
 
         [Parameter()]
         [System.Boolean]
-        $ClearDisk
+        $ClearDisk,
+
+        [Parameter()]
+        [System.Boolean]
+        $DevDrive,
+
+        [Parameter()]
+        [System.Boolean]
+        $UseUnallocatedSpace
     )
 
     Write-Verbose -Message ( @(
@@ -395,8 +409,13 @@ function Set-TargetResource
             } # if
         } # if
 
-        # Do we need to create a new partition?
-        if (-not $partition)
+        <#
+            There are two instances when we attempt to create a new partition:
+            1. When there are no partitions matching the drive letter the user entered.
+            2. When the user has advised us that they want to create a new partition on the disk's
+               unallocated space, regardless of whether there is one that matches the $size parameter already.
+        #>
+        if (-not $partition -bor $UseUnallocatedSpace)
         {
             # Attempt to create a new partition
             $partitionParams = @{
@@ -560,6 +579,11 @@ function Set-TargetResource
                 $($script:localizedData.FormattingVolumeMessage -f $formatVolumeParameters.FileSystem)
             ) -join '' )
 
+        if ($DevDrive)
+        {
+            $formatVolumeParameters['DevDrive'] = $DevDrive
+        }
+
         # Format the volume
         $volume = $partition | Format-Volume @formatVolumeParameters
     }
@@ -597,6 +621,11 @@ function Set-TargetResource
                         $formatParam.Add('AllocationUnitSize', $AllocationUnitSize)
                     }
 
+                    if ($PSBoundParameters.ContainsKey('DevDrive'))
+                    {
+                        $formatParam.Add('DevDrive', $DevDrive)
+                    }
+
                     $Volume | Format-Volume @formatParam
                 }
             } # if
@@ -671,6 +700,12 @@ function Set-TargetResource
     .PARAMETER ClearDisk
         Specifies if the disks partition schema should be removed entirely, even if data and OEM
         partitions are present. Only possible with AllowDestructive enabled.
+
+    .PARAMETER DevDrive
+        Specifies if the volume should be formatted as a Dev Drive.
+
+    .PARAMETER UseUnallocatedSpace
+        Specifies that a new partition and volume should be formatted onto unallocated space on the disk.
 #>
 function Test-TargetResource
 {
@@ -719,7 +754,15 @@ function Test-TargetResource
 
         [Parameter()]
         [System.Boolean]
-        $ClearDisk
+        $ClearDisk,
+
+        [Parameter()]
+        [System.Boolean]
+        $DevDrive,
+
+        [Parameter()]
+        [System.Boolean]
+        $UseUnallocatedSpace
     )
 
     Write-Verbose -Message ( @(
@@ -750,6 +793,42 @@ function Test-TargetResource
         return $false
     } # if
 
+    # Check Dev Drive feature is enabled and that the user inputted ReFS as the file system.
+    if ($PSBoundParameters.ContainsKey('DevDrive'))
+    {
+        Assert-DevDriveFeatureAvailable
+        Assert-DevDriveFormatOnReFsFileSystemOnly -FSFormat $FSFormat
+
+        $tempPartition = Get-Partition `
+            -DriveLetter $DriveLetter `
+            -ErrorAction SilentlyContinue | Select-Object -First 1
+
+        # For unintialized disks, the largest free extent is the size of the disk.
+        if ($disk.PartitionStyle -ne 'RAW' )
+        {
+            $currentDiskFreeSpace = $disk.LargestFreeExtent
+        }
+        else
+        {
+            $currentDiskFreeSpace = $disk.Size
+        }
+
+        # User is attempting to create a new Dev Drive volume in a new partition
+        if ($null -eq $tempPartition)
+        {
+            <#
+                The Dev Drive will be created within the largest block of continguous unallocated space
+                available. So we need to check that the space is big enough to create the Dev Drive in.
+            #>
+            Assert-DiskHasEnoughSpaceToCreateDevDrive `
+                -UserDesiredSize $Size `
+                -CurrentDiskFreeSpace $currentDiskFreeSpace `
+                -DiskNumber $Disk.Number
+        }
+
+        Assert-DevDriveSizeMeetsMinimumRequirement -UserDesiredSize $Size
+    }
+
     if ($disk.IsOffline)
     {
         Write-Verbose -Message ( @(

source/DSCResources/DSC_Disk/DSC_Disk.schema.mof

@@ -12,4 +12,6 @@ class DSC_Disk : OMI_BaseResource
     [Write, Description("Specifies the file system format of the new volume."), ValueMap{"NTFS","ReFS"}, Values{"NTFS","ReFS"}] String FSFormat;
     [Write, Description("Specifies if potentially destructive operations may occur.")] Boolean AllowDestructive;
     [Write, Description("Specifies if the disks partition schema should be removed entirely, even if data and OEM partitions are present. Only possible with AllowDestructive enabled.")] Boolean ClearDisk;
+    [Write, Description("Specifies if the volume should be formatted as a Dev Drive.")] Boolean DevDrive;
+    [Write, Description("Specifies that a new partition and volume should be formatted onto unallocated space in the disk.")] Boolean UseUnallocatedSpace;
 };

source/Examples/Resources/Disk/3-Disk_InitializeDiskWithADevDrive.ps1

@@ -0,0 +1,69 @@
+<#PSScriptInfo
+.VERSION 1.0.0
+.GUID 3f629ab7-358f-4d82-8c0a-556e32514e3e
+.AUTHOR DSC Community
+.COMPANYNAME DSC Community
+.COPYRIGHT Copyright the DSC Community contributors. All rights reserved.
+.TAGS DSCConfiguration
+.LICENSEURI https://github.com/dsccommunity/StorageDsc/blob/main/LICENSE
+.PROJECTURI https://github.com/dsccommunity/StorageDsc
+.ICONURI
+.EXTERNALMODULEDEPENDENCIES
+.REQUIREDSCRIPTS
+.EXTERNALSCRIPTDEPENDENCIES
+.RELEASENOTES First version.
+.PRIVATEDATA 2016-Datacenter,2016-Datacenter-Server-Core
+#>
+
+#Requires -module StorageDsc
+
+<#
+    .DESCRIPTION
+        This configuration will wait for disk 2 to become available, and then make the disk available as
+        two new Dev Drive volumes, 'E' and 'F', with 'F' using all available space after 'E' has been
+        created.
+#>
+Configuration Disk_InitializeDiskWithADevDrive
+{
+    Import-DSCResource -ModuleName StorageDsc
+
+    Node localhost
+    {
+        WaitForDisk Disk2
+        {
+            DiskId = '5E1E50A401000000001517FFFF0AEB84' # Disk 2
+            DiskIdType = 'UniqueId'
+            RetryIntervalSec = 60
+            RetryCount = 60
+        }
+
+        # Will create a Dev Drive of 50Gb requiring the disk to have 50Gb of unallocated space.
+        Disk DevDriveVolume1
+        {
+            DiskId = '5E1E50A401000000001517FFFF0AEB84'
+            DiskIdType = 'UniqueId'
+            DriveLetter = 'E'
+            FSFormat = 'ReFS'
+            FSLabel = 'DevDrive'
+            DevDrive = $true
+            Size = 50Gb
+            UseUnallocatedSpace = $true
+            DependsOn = '[WaitForDisk]Disk2'
+        }
+
+        <#
+            Will attempt to create a Dev Drive volume using the rest of the space on the disk assuming
+            that the rest of the space is greater than the minimum size for Dev Drive volumes (50Gb).
+        #>
+        Disk DevDriveVolume2
+        {
+            DiskId = '5E1E50A401000000001517FFFF0AEB84'
+            DiskIdType = 'UniqueId'
+            DriveLetter = 'F'
+            FSFormat = 'ReFS'
+            FSLabel = 'DevDrive'
+            DevDrive = $true
+            DependsOn = '[Disk]DevDriveVolume1'
+        }
+    }
+}