Scheduling of I/O in an SSD environment

摘要

A system and method for effectively scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The characteristics of corresponding storage devices are used to schedule I/O requests to the storage devices in order to maintain relatively consistent response times at predicted times. In order to reduce a likelihood of unscheduled behaviors of the storage devices, the storage controller is configured to schedule proactive operations on the storage devices that will reduce a number of occurrences of unscheduled behaviors.

主权项

1. A computer system comprising:
a plurality of storage devices configured to store data; and a data storage controller configured to:
determine that a particular storage device is in a particular operational state;determine a length of time that the particular storage device has been in the particular operational state;based on the particular operational state and the length of time the particular storage device has been in the particular operational state, predicting when a particular storage device of the plurality of storage devices will exhibit an unscheduled behavior comprising a relatively high response latency or a relatively low throughput; andbased on the prediction, schedule one or more proactive operations in order to reduce a likelihood of an occurrence of the unscheduled behavior.