1. An operating system embodied in computer-readable media for a computer system having a processor, a memory and at least one data storage device, the operating system comprising: an operating system kernel; at least one filesystem controlling access to the at least one data storage device; and a toolkit module installed within the operating system kernel; wherein the toolkit module monitors input/output (I/O) calls communicated via a datapath between at least one software application being executed on the processor and the filesystem; and wherein the toolkit module inserts one or more tools into the datapath, the one or more tools each executing a predefined function based on observation of a first set of the I/O calls being communicated in the datapath.