Patent ID: 7539815

Claim:
A method for managing tasks of a disk, comprising: formulating a plurality of ranges of a ratio between an amount of dirty data currently in a cache and a predetermined dirty data threshold, the ranges including all values of the ratio between 0% and 100%, at least one range having a lower bound greater than 0% and an upper bound less than 100%; formulating numbers of destage tasks currently being handled by the disk; for each pair of a given range and a given number of destage tasks, formulating a correspondence to a respective predetermined number of destage tasks to be delegated to the disk; in response to determining a range of the ratio for the cache and a number of destage tasks currently being handled by the disk, delegating a number of destage tasks to the disk according to the correspondence; and if the number of destage tasks delegated according to the correspondence is zero, performing one or more fetches from the disk.