SplitIo class

This class is the parent class for split IO events.

The following syntax is simplified from MOF code.


class SplitIo : MSNT_SystemTrace


The SplitIo class does not define any members.


To enable split IO events in an NT Kernel logging session, specify the EVENT_TRACE_FLAG_SPLIT_IO flag in the EnableFlags member of an EVENT_TRACE_PROPERTIES structure when calling the StartTrace function.

Event trace consumers can implement special processing for split IO events by calling the SetTraceCallback function and specifying SplitIoGuid as the pGuid parameter. Use the following event type to identify the actual event when consuming events.

Event type Description
Event type value, 32 Split IO event. The SplitIo_Info MOF class defines the event data for this event.


Split IO events indicate that the IO requests have been split into multiple disk IO requests due to the underlying mirroring disk hardware.


Minimum supported client
Windows Vista [desktop apps only]
Minimum supported server
Windows Server 2008 [desktop apps only]