The DISK_INFO_EX structure provides information about a disk.

 struct diskinfoex {
   LdmObjectId id;
   LONGLONG length;
   LONGLONG freeBytes;
   unsigned long bytesPerTrack;
   unsigned long bytesPerCylinder;
   unsigned long bytesPerSector;
   unsigned long regionCount;
   unsigned long dflags;
   unsigned long deviceType;
   unsigned long deviceState;
   unsigned long busType;
   unsigned long attributes;
   unsigned long maxPartitionCount;
   boolean isUpgradeable;
   boolean maySwitchStyle;
   PARTITIONSTYLE partitionStyle;
   [switch_is(partitionStyle)] union {
     [case(PARTITIONSTYLE_MBR)] 
       struct {
       unsigned long signature;
     } mbr;
     [case(PARTITIONSTYLE_GPT)] 
       struct {
       GUID diskId;
     } gpt;
     [default]       ;
   };
   int portNumber;
   int targetNumber;
   int lunNumber;
   LONGLONG lastKnownState;
   LdmObjectId taskId;
   int cchName;
   int cchVendor;
   int cchDgid;
   int cchAdapterName;
   int cchDgName;
   int cchDevInstId;
   [size_is(cchName)] wchar_t* name;
   [size_is(cchVendor)] wchar_t* vendor;
   [size_is(cchDgid)] byte* dgid;
   [size_is(cchAdapterName)] wchar_t* adapterName;
   [size_is(cchDgName)] wchar_t* dgName;
   [size_is(cchDevInstId)] wchar_t* devInstId;
 };
 typedef struct diskinfoex DISK_INFO_EX;

id: Specifies the OID of the disk.

length: Size of the disk in bytes.

freeBytes: Number of unallocated bytes on the disk.

bytesPerTrack: Size of a disk track in bytes.

bytesPerCylinder: Size of a disk cylinder in bytes.

bytesPerSector: Size of a disk sector in bytes.

regionCount: Total number of regions on the disk.

dflags: Disk type of the disk. The value of this field is generated by combining zero or more of the applicable flags with a logical OR operation.

Value	Meaning
DISK_AUDIO_CD 0x00000001	Disk is an audio CD.
DISK_NEC98 0x00000002	This value is obsolete and MUST NOT be returned.
DISK_FORMATTABLE_DVD 0x00000004	Disk is a DVD that can be formatted.
DISK_MEMORY_STICK 0x00000008	Disk is a memory stick.
DISK_NTFS_NOT_SUPPORTED 0x000000010	Disk does not support being formatted as NTFS.

deviceType: Device type of the disk.

Value	Meaning
DEVICETYPE_UNKNOWN 0x00000000	Device is of an unknown type.
DEVICETYPE_VM 0x00000001	Device is a dynamic disk.
DEVICETYPE_REMOVABLE 0x00000002	Device uses removable media.
DEVICETYPE_CDROM 0x00000003	Device is a CD-ROM.
DEVICETYPE_FDISK 0x00000004	Device is a basic disk.
DEVICETYPE_DVD 0x00000005	Device is a DVD.

deviceState: Device state of the disk.

Value	Meaning
DEVICESTATE_UNKNOWN 0x00000000	Disk is in an unknown state.
DEVICESTATE_HEALTHY 0x00000001	Disk is fully functional.
DEVICESTATE_NO_MEDIA 0x00000002	Disk has no media.
DEVICESTATE_NOSIG 0x00000004	Disk has an invalid signature.
DEVICESTATE_BAD 0x00000008	Disk experienced a geometry failure.
DEVICESTATE_NOT_READY 0x00000010	Disk is not ready yet.
DEVICESTATE_MISSING 0x00000020	Disk is no longer available.
DEVICESTATE_OFFLINE 0x00000040	Disk is offline.
DEVICESTATE_FAILING 0x00000080	Disk experienced a physical I/O error.
DEVICESTATE_IMPORT_FAILED 0x00000100	Disk belongs to a group whose import failed. See disk group import.
DEVICESTATE_UNCLAIMED 0x00000200	Disk belongs to a foreign disk group.

busType: Type of bus on which the disk resides.

Value	Meaning
BUSTYPE_UNKNOWN 0x00000000	Bus type is unknown.
BUSTYPE_IDE 0x00000001	Disk resides on an IDE bus.
BUSTYPE_SCSI 0x00000002	Disk resides on an SCSI bus.
BUSTYPE_FIBRE 0x00000003	Disk resides on a fiber channel bus.
BUSTYPE_USB 0x00000004	Disk resides on a USB.
BUSTYPE_SSA 0x00000005	Disk resides on an SSA bus.
BUSTYPE_1394 0x00000006	Disk resides on an IEEE 1394 bus.

attributes: Bitmap of disk attributes.

Value	Meaning
DEVICEATTR_NONE 0x00000000	Disk has no attributes.
DEVICEATTR_RDONLY 0x00000001	Disk is read-only.
DEVICEATTR_NTMS 0x00000002	This value is obsolete.

maxPartitionCount: Maximum number of partitions on the disk.

isUpgradeable: Boolean value that indicates if the disk can be converted to a dynamic disk. True if the disk is basic, healthy, and has 512-byte sectors.

Value	Meaning
FALSE 0	Disk cannot be encapsulated or converted to a dynamic disk.
TRUE 1	Disk can be encapsulated or converted to a dynamic disk.

maySwitchStyle: Boolean value that indicates if the disk's partition style can be changed from MBR to GPT, or changed from GPT to MBR.

Value	Meaning
FALSE 0	Partition style of the disk cannot be changed.
TRUE 1	Partition style of the disk can be changed between MBR and GPT.

partitionStyle: Value from the PARTITIONSTYLE enumeration that indicates the disk's partitioning style.

(unnamed union): A union that contains either a signature or a diskId, depending on the value of partitionStyle:

signature: Signature of the disk. The disk signature is not guaranteed to be unique across machines.<8>

diskId: GUID, as specified in [MS-DTYP], section 2.3.4.1, of the disk.<9>

portNumber: SCSI port number of the disk.

targetNumber: SCSI target identifier of the disk.

lunNumber: SCSI LUN of the disk.

lastKnownState: Modification sequence number of the disk.

taskId: The task identifier of the associated user request. If no request is made, the value is 0.

cchName: Length of the hard disk's physical name, including the terminating null character.

cchVendor: Length of the disk's vendor name, including the terminating null character.

cchDgid: Length of the disk's group identification handle, including the terminating null character.

cchAdapterName: Length of the disk's adapter name, including the terminating null character.

cchDgName: Length of the disk's group name, including the terminating null character.

cchDevInstId: Length of the disk's device instance path, including the terminating null character.

name: Null-terminated physical name of the hard disk. For example: '\device\Harddisk1'.

vendor: Null-terminated name of the hard disk vendor. This is the disk vendor's disk model name. For example: "SEAGATE ST34573N SCSI Disk Device".

dgid: Specifies the object identifier of the disk's disk group.

adapterName: Null-terminated name of the disk adapter. For example: "Adaptec AHA-2940U2W - Ultra2 SCSI".

dgName: Null-terminated name for the disk's disk group, if the disk is dynamic.

devInstId: Null-terminated device instance path of the disk with the backslashes replaced by "#", "\\?\" prepended to the beginning, and the Pnp disk class GUID, as specified in [MS-DTYP] section 2.3.4.3, appended to the end. For example: "\\?\ide#diskwdc_wd1600jd-75hbb0_____________________08.02d08#5&15c8d966&0&0.0.0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}".