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PREEMPTIVE_OS_MOVEFILE
Description:
This wait type is when a thread is calling the Windows MoveFile function.
(Books Online description: N/A)
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Added in SQL Server version:
2008
Removed in SQL Server version:
N/A
Extended Events wait_type value:
The map_key value in sys.dm_xe_map_values is 459 in 2008 and 2008 R2, 507 in 2012, and 523 in 2014 RTM. After 2014 RTM, you must check the DMV to get the latest value as some map_key values have changed in later builds.
Other information:
I have not seen this wait type be a noticeable contention point.
Note that when a thread calls out to Windows, the thread changes from non-preemptive (SQL Server controls the thread) to preemptive (Windows controls the thread) mode. The thread’s state will be listed as RUNNING, as SQL Server doesn’t know what Windows is doing with the thread.
Known occurrences in SQL Server (list number matches call stack list):
- Moving a file (in this case, as part of creating a new error log file)
Abbreviated call stacks (list number matches known occurrences list):
- SOS_Task::PopWait+b1
SOS_ExternalAutoWait::~SOS_ExternalAutoWait+7c
CErrorReportingManager::InitErrorLog+7ce
DbccCommand::Execute+153
CStmtDbcc::XretExecute+7cd
CMsqlExecContext::ExecuteStmts<1,1>+427
CMsqlExecContext::FExecute+a43
CSQLSource::Execute+86c
CStmtExecProc::XretLocalExec+25a
CStmtExecProc::XretExecExecute+4e8
CXStmtExecProc::XretExecute+38
CMsqlExecContext::ExecuteStmts<1,1>+427
CMsqlExecContext::FExecute+a43
CSQLSource::Execute+86c
process_request+a57
process_commands+4a3
SOS_Task::Param::Execute+21e
SOS_Scheduler::RunTask+ab