This white paper describes the
FILESTREAM feature of SQL Server 2008, which allows storage of and efficient
access to BLOB data using a combination of SQL Server 2008 and the NTFS file
system. It covers choices for BLOB storage, configuring Windows and SQL Server
for using FILESTREAM data, considerations for combining FILESTREAM with other
features, and implementation details such as partitioning and performance.
http://msdn.microsoft.com/en-us/library/cc949109.aspx