MSFT_Partition class

Represents a partition on a disk.

The following syntax is simplified from Managed Object Format (MOF) code.

Syntax

class MSFT_Partition : MSFT_StorageObject
{
  UInt32  DiskNumber;
  UInt32  PartitionNumber;
  Char16  DriveLetter;
  String  AccessPaths[];
  UInt16  OperationalStatus;
  UInt16  TransitionState;
  UInt64  Size;
  UInt16  MbrType;
  String  GptType;
  String  Guid;
  Boolean IsReadOnly;
  Boolean IsOffline;
  Boolean IsSystem;
  Boolean IsBoot;
  Boolean IsActive;
  Boolean IsHidden;
  Boolean IsShadowCopy;
  Boolean NoDefaultDriveLetter;
};

Members

The MSFT_Partition class has these types of members:

Methods

The MSFT_Partition class has these methods.

Method Description
AddAccessPath Adds a mount path or drive letter assignment to the partition.
DeleteObject Deletes the partition and corresponding volume.
GetAccessPaths Retrieves all mount points and drive letters that can be used to access the partition.
GetSupportedSize Retrieves the minimum and maximum sizes that the partition can be resized to using the Resize method.
Offline Takes the partition offline by dismounting the associated volume (if one exists).
Online Brings the partition online by mounting the associated volume (if one exists).
RemoveAccessPath Remove an access path from the partition.
Resize Resizes the partition and any associated file system volume to the size specified by the Size parameter.
SetAttributes Sets various attributes and properties of the partition.

Properties

The MSFT_Partition class has these properties.

AccessPaths

Data type: String array

Access type: Read-only

An array of strings containing the various mount points for the partition. This list includes drive letters, in addition to mounted folders.

DiskNumber

Data type: UInt32

Access type: Read-only

Qualifiers: Required, ModelCorrespondence {"MSFT_Disk.Number"}

The operating system's number for the disk that contains this partition. Disk numbers may not necessarily remain the same across restarts.

DriveLetter

Data type: Char16

Access type: Read-only

The currently assigned drive letter for the partition. This property is NULL if no drive letter has been assigned.

GptType

Data type: String

Access type: Read-only

The partition's GPT type. This property is only valid when the disk's PartitionStyle property is GPT and will be NULL for all other partition styles.

Value Meaning
System Partition
c12a7328-f81f-11d2-ba4b-00a0c93ec93b
An EFI system partition.
Microsoft Reserved
e3c9e316-0b5c-4db8-817d-f92df00215ae
A Microsoft reserved partition.
Basic data
ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
A basic data partition. This is the data partition type that is created and recognized by Windows.
Only partitions of this type can be assigned drive letters, receive volume GUID paths, host mounted folders (also called volume mount points) and be enumerated by calls to FindFirstVolume and FindNextVolume.
LDM Metadata
5808c8aa-7e8f-42e0-85d2-e1e90434cfb3
A Logical Disk Manager (LDM) metadata partition on a dynamic disk.
LDM Data
af9b60a0-1431-4f62-bc68-3311714a69ad
The partition is an LDM data partition on a dynamic disk.
Microsoft Recovery
de94bba4-06d1-4d40-a16a-bfd50179d6ac
A Microsoft recovery partition.

Guid

Data type: String

Access type: Read-only

The partition's GPT GUID. This property is only valid when the disk's PartitionStyle property is GPT and will be NULL for all other partition styles.

IsActive

Data type: Boolean

Access type: Read-only

If TRUE, the partition is active and can be used to start the system. This property is only valid when the disk's PartitionStyle property is MBR and will be NULL for all other partition styles.

IsBoot

Data type: Boolean

Access type: Read-only

If TRUE, the partition is the current boot partition.

IsHidden

Data type: Boolean

Access type: Read-only

If TRUE, the partition is not detected by the mount manager. As a result, the partition does not receive a drive letter, does not receive a volume GUID path, does not host volume mount points, and is not enumerated by calls to FindFirstVolume and FindNextVolume. This ensures that applications such as Disk Defragmenter do not access the partition. The Volume Shadow Copy Service (VSS) uses this attribute on its shadow copies.

IsOffline

Data type: Boolean

Access type: Read-only

If TRUE, this partition is currently offline.

IsReadOnly

Data type: Boolean

Access type: Read-only

If TRUE, this is a read-only partition.

IsShadowCopy

Data type: Boolean

Access type: Read-only

If TRUE, the partition is a shadow copy of another partition. This attribute is used by VSS. This attribute is an indication for file system filter driver-based software (such as antivirus programs) to avoid attaching to the volume. An application can use this attribute to differentiate a shadow copy partition from a production partition. For example, an application that performs a fast recovery will break a shadow copy virtual disk by clearing the read-only and hidden attributes and this attribute. This attribute is set when the shadow copy is created and cleared when the shadow copy is broken.

IsSystem

Data type: Boolean

Access type: Read-only

If TRUE, this is a system partition.

MbrType

Data type: UInt16

Access type: Read-only

The partition's MBR type. This property is only valid when the disk's PartitionStyle property is MBR and will be NULL for all other partition styles.

FAT12 (1)

FAT16 (4)

Extended (5)

Huge (6)

IFS (7)

FAT32 (12)

NoDefaultDriveLetter

Data type: Boolean

Access type: Read-only

If TRUE, the operating system does not assign a drive letter automatically when the partition is discovered. This is only honored for GPT disks and is assumed to be FALSE for MBR disks. This attribute is useful in storage area network (SAN) environments.

OperationalStatus

Data type: UInt16

Access type: Read-only

Qualifiers: Values ( "Unknown", "Online", "No Media", "Failed", "Offline" ), ValueMap ( "0", "1", "3", "5", "4" )

The operational status of the partition.

PartitionNumber

Data type: UInt32

Access type: Read-only

Qualifiers: Required

The operating system's number for the partition. Ordering is based on the partition's offset, relative to other partitions. This means that the value for this property may change based off of the partition configuration in the offset range preceding this partition.

Size

Data type: UInt64

Access type: Read-only

Total size of the partition, measured in bytes.

TransitionState

Data type: UInt16

Access type: Read-only

The transition state of the partition. One of the following values.

Value Meaning
0
This value is reserved for system use.
1
The partition is stable. No configuration activity is currently in progress.
2
The partition is being extended.
3
The partition is being shrunk.
4
The partition is being automagically reconfigured.
8
The partition is being restriped.

Remarks

Starting in Windows 10: MSFT_Partition derives from MSFT_StorageObject.

Requirements

Minimum supported client
Windows 8 [desktop apps only]
Minimum supported server
Windows Server 2012 [desktop apps only]
Namespace
Root\Microsoft\Windows\Storage
MOF
Storagewmi.mof