Method, apparatus and computer program product for managing input/output

An apparatus of managing an input/output (I/O), comprising:

• at least one processing unit;
• at least one memory coupled to the at least one processing unit and storing instructions for execution by the at least one processing unit, the instructions, when executed by the at least one processing unit, causing the apparatus to perform acts including:
• in response to receiving a first I/O request of a first type for a storage device, determining whether there exists at least one credit available to the first type of I/O requests, each of the at least one credit indicating I/O processing capability reserved by the storage device for the first type of I/O requests;
• allocating a first credit to the first I/O request based on a result of the determining;
• performing, by using the first credit, an I/O operation requested by the first I/O request on the storage device;
• and
• in response to completion of the I/O operation, recycling the first credit for use by a subsequent I/O request;
• wherein the storage device is a redundant array of independent disks (RAID), and wherein the I/O processing capability is represented by a number of I/O operations that the RAID is able to process concurrently.

A computer program product comprising a non-transient computer storage medium having stored therein machine executable instructions of one or more software programs, wherein the machine executable instructions when executed by an apparatus, cause the apparatus:

• in response to receiving a first I/O request of a first type for a storage device, to determine whether there exists at least one credit available to the first type of I/O requests, each of the at least one credit indicating I/O processing capability reserved by the storage device for the first type of I/O requests;
• to allocate a first credit to the first I/O request based on a result of the determining;
• to perform, by using the first credit, an I/O operation requested by the first I/O request on the storage device;
• and
• in response to completion of the I/O operation, to recycle the first credit for use by a subsequent I/O request;
• wherein the storage device is a redundant array of independent disks (RAID), and wherein the I/O processing capability is represented by a number of I/O operations that the RAID is able to process concurrently.