EWF API Functions (Standard 7 SP1)

7/8/2014

Enhanced Write Filter (EWF) functions let you create, configure, and protected EWF volumes and manage HORM support.

In This Section

The following table shows the functions that are used to query and configure protected Enhanced Write Filter volumes.

Function	Description
EwfMgrCheckpoint	This function adds a checkpoint overlay level on the specified EWF-protected volume.
EwfMgrClearCommand	This function clears any pending commands that would have occurred on the next restart.
EwfMgrClose	This function closes an EWF-protected volume.
EwfMgrCommit	This function commits all current level data in the overlay to the EWF-protected volume.
EwfMgrCommitAndDisableLive	This function immediately commits all current level data to the EWF-protected volume and then disabled EWF. This function does not require a restart.
EwfMgrCommitFile	This function commits a single file to the protected volume. The size of the file or its location must not have changed before the file is committed.
EwfMgrDisable	This function disables a currently enabled overlay on the specified EWF-protected volume.
EwfMgrEnable	This function enables a currently disabled overlay on the specified EWF-protected volume.
EwfMgrGetDriveLetterFromVolumeName	This function retrieves the drive letter for the specified volume name.
EwfMgrGetPersistentData	This function retrieves the persistent data for an EWF-protected volume.
EwfMgrGetProtectedVolumeConfig	This function retrieves the configuration information for an EWF-protected volume.
EwfMgrOpenProtected	This function opens an EWF-protected volume.
EwfMgrRestore	This function restores one overlay level on the specified EWF-protected volume, discarding all changes in the current level.
EwfMgrSetLevel	This function sets the overlay level on an EWF-protected volume.
EwfMgrSetPersistentData	This function sets the persistent data for an EWF-protected volume.

The following table shows the functions that are used to query and configure the EWF overlay store volumes.

Function	Description
EwfMgrGetOverlayStoreConfig	This function retrieves the configuration information for the EWF overlay store.
EwfMgrOpenOverlayStore	This function retrieves the name of the overlay store volume, if it exists.
EwfMgrRegisterLowSpaceNotification	This function registers for a low space notification when the available bytes in the overlay reach a specified threshold.

The following table shows the functions that are used to obtain and work with a list of EWF-protected volumes.

Function	Description
EwfMgrGetProtectedVolumeList	This function retrieves a list of all the EWF-protected volumes.
EwfMgrVolumeNameEntryPop	This function removes the current entry from the EWF volume name list and frees the current memory entry.
EwfMgrVolumeNameListDelete	This function deletes all entries in the EWF volume name list.
EwfMgrVolumeNameListIsEmpty	This function determines whether the EWF volume name list is empty.

The following table shows the functions that are used to manage Hibernate Once/Resume Many (HORM).

Function	Description
EwfMgrActivateHORM	This function enables HORM support at run-time.
EwfMgrDeactivateHORM	This function disables HORM support.
EwfMgrIsHORMActivated	This function returns the current status of HORM.

See Also

Concepts

EWF API
EWF API Code Sample