Device selection by a disk adapter scheduler

US6904470B1 · kind B1 · utility

Assignee

• EMC Corporation · US

Inventors

• Adi Ofer · Wellesley, US
• William P. Powers, Jr. · Sutton, US
• Gilad Sade · Newton, US
• Amit Kumar · Folsom, US
• Stephen Richard Ives · West Boylston, US
• Ran Margalit · Ramat HaSharon, IL
• Daniel Rabinovich · Wrentham, US
• Peng Yin · Shanghai, CN

Key dates

• Filing date: Mar 26, 2003
• Grant date: Jun 7, 2005
• Expiry date: Mar 26, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F11/2056
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A scheduler for selecting a logical volume for scheduling pending I/O tasks for job generation. The scheduler includes a main scheduler that selects from among multiple sub-schedulers that operate according to different scheduling approaches, e.g., high priority read I/O request scheduling, urgency of non-read I/O tasks, as well as load balancing and round robin schemes. In selecting a sub-scheduler, the main scheduler considers the amount of time allocated to performing read I/O requests, as well as the level of urgency associated with the logical volumes and the disk adapter that manages those logical volumes for non-read I/O tasks.