DismountNtmsMedia function (ntmsapi.h)

Article
10/13/2021

[Removable Storage Manager is no longer available as of Windows 7 and Windows Server 2008 R2.]

The DismountNtmsMedia function queues a command to move the specified media in a drive to its storage. This function should be paired with the MountNtmsMedia function.

Syntax

DWORD DismountNtmsMedia(
  [in] HANDLE      hSession,
  [in] LPNTMS_GUID lpMediaId,
  [in] DWORD       dwCount,
  [in] DWORD       dwOptions
);

Parameters

[in] hSession

Handle to the session returned by the OpenNtmsSession function.

[in] lpMediaId

Array of at least one logical medium or side.

[in] dwCount

Number of media identifiers in the lpMediaId parameter.

[in] dwOptions

Options. This parameter can be the following value.

Value	Meaning
NTMS_DISMOUNT_DEFERRED	Marks media state as Dismountable, and keeps the medium in the drive. Subsequent mount requests are satisfied using dismounted or dismountable drives. The default is to dismount immediately.
NTMS_DISMOUNT_IMMEDIATE	Dismount the drive immediately.

Return value

This function returns one of the following values.

Value	Meaning
ERROR_ACCESS_DENIED	NTMS_USE_ACCESS to the media pool or library that contains the media is denied. Other security errors are also possible, but they would indicate a security subsystem error.
ERROR_DATABASE_FAILURE	The database is inaccessible or damaged.
ERROR_DATABASE_FULL	The database is full.
ERROR_DEVICE_NOT_AVAILABLE	One or more resources required to perform the dismount are not currently available (probably disabled).
ERROR_INVALID_LIBRARY	The library that contains the media is not valid.
ERROR_INVALID_MEDIA	At least one of the specified media is not valid.
ERROR_INVALID_STATE	An unexpected media or device state occurred during dismount.
ERROR_MEDIA_OFFLINE	The specified media is offline.
ERROR_MEDIA_NOT_AVAILABLE	One or more media resources required to perform the mount are not currently available (probably disabled).
ERROR_NOT_ENOUGH_MEMORY	A memory allocation failure occurred during processing.
ERROR_SUCCESS	The media dismount has been queued.
ERROR_TIMEOUT	The time-out event expired while the application attempted to acquire one or more resources.

Remarks

An application must use the DismountNtmsMedia function to release the drive resource after the application has used the specified medium. Unreleased media cannot be used by other RSM sessions.

The DismountNtmsMedia function returns as soon as the operation is queued with RSM. The application can wait for the side state to become idle.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	ntmsapi.h
Library	Ntmsapi.lib
DLL	Ntmsapi.dll