The cache manager is a set of kernel-mode functions and system threads that cooperate with the memory manager to provide data caching for all Windows file system drivers (both local and network). In this chapter, we’ll explain how the cache manager, including its key internal data structures and functions, works; how it is sized at system initialization time; how it interacts with other elements of the operating system; and how you can observe its activity through performance counters. We’ll also describe the five flags on the Windows CreateFile function that affect file caching.
None of the cache manager’s internal functions are outlined in this chapter beyond the depth required to explain how the cache manager works. The programming interfaces to the cache manager are documented in the Windows Driver Kit (WDK). For more information about the WDK, see http://www.microsoft.com/whdc/devtools/wdk/default.mspx.