Abstract: A job profile is received that includes characteristics of a job to be executed, where the characteristics of the job profile relate to map tasks and reduce tasks of the job. The map tasks produce intermediate results based on input data, and the reduce tasks produce an output based on the intermediate results. The characteristics of the job profile include at least one particular characteristic that varies according to a size of data to be processed. The at least one particular characteristic of the job profile is set based on the size of the data to be processed.

Abstract: A system includes a number of hard disk drives and a controller. Each hard disk drive is selected from a number of different hard disk drive types. Each hard disk drive type has a different speed at which the hard disk drives of the hard disk drive type rotate to read and write data. At least one of the hard disk drives is of a different hard disk drive type than at least one other of the hard disk drives. The controller, responsive to a request to write particular data to the hard disk drives, is to select a given hard disk drive of the hard disk drives based on a type of the particular data, and is to write the particular data to the given hard disk drive.