Abstract: Described are techniques for determining whether to move data between devices. A first cost metric is determined for a first device and a second device. At least one portion of data is selected for movement from one of the first device and the second device to another of the first device and the second device. A second cost metric is determined for the first device and the second device based on moving said at least one portion of data between said first device and said second device. It is determined using the first cost metric and the second cost metric whether to move the at least one portion of data.

Abstract: A method and apparatus for scheduling jobs having a staging time and a processing time are described. In one method, the jobs are divided into subsets based on a predetermined criteria such as depending on whether the staging time is longer than the processing time. In this method, the jobs in each subset are ordered independently. The jobs are then scheduled by alternating between the ordered subsets. In a second method, the jobs are again divided into subsets based on a predetermined criteria such as depending on whether the staging time is longer than the processing time. The jobs in each subset are ordered independently. The jobs in one subset are then simply appended to the other subset. In a third method, the jobs are ordered according to a predetermined criterion into a list and are executed by alternating between both ends of the list. The invention is also applicable to scheduling jobs having a destaging time.