The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 9: Investigating FILESTREAM DatabasesFS_GARBAGE_COLLECTOR_SHUTDOWNThis wait type occurs during the cleanup process of a garbage collection cycle. It indicatesthat the garbage collector is waiting for the cleanup tasks to be completed.FS_HEADER_RWLOCKThis wait type indicates that the process is waiting to obtain access to the FILESTREAMheader file for read or write operation. The FILESTREAM header is a disk file locatedin the FILESTREAM data container and is named filestream.hdr. This file containsimportant metadata information that SQL Server uses to manage the FILESTREAM dataassociated with a given database. Unlike FILESTREAM data files, SQL Server keeps anexclusive lock on the filestream.hdr file.FS_LOGTRUNC_RWLOCKThis wait type indicates that the process is trying to access FILESTREAM log truncation,either to perform a log truncate operation, or to disable log truncation prior to a backupor restore operation.FSA_FORCE_OWN_XACTThis wait type occurs when a FILESTREAM file I/O operation needs to bind to theassociated transaction, but the transaction is currently owned by another session.349