Reconstruct reads in a raid array with dynamic geometries

A method for use in a computing system, the method comprising:

• receiving the read and write requests in a data storage subsystem, wherein the subsystem comprises a plurality of data storage locations on a plurality of storage devices;
• configuring a first subset of the storage devices for use in a first RAID layout, the first RAID layout including a first set of redundant data;
• configuring a second subset of the storage devices for use in a second RAID layout, the second RAID layout including a second set of redundant data;
• and
• configuring an additional device not included in either the first subset or the second subset to store redundant data for both the first RAID layout and the second RAID layout;
• initiating a reconstruct read corresponding to a given read request directed to a particular storage device of the plurality of storage devices, in response to determining the particular storage device is exhibiting a non-error related relatively slow read response.

A computer readable storage medium storing program instructions, wherein the program instructions are executable to:

• receive the read and write requests in a data storage subsystem, wherein the subsystem comprises a plurality of data storage locations on a plurality of storage devices;
• configure a first subset of the storage devices for use in a first RAID layout, the first RAID layout including a first set of redundant data;
• configure a second subset of the storage devices for use in a second RAID layout, the second RAID layout including a second set of redundant data;
• and
• configure an additional device not included in either the first subset or the second subset to store redundant data for both the first RAID layout and the second RAID layout;
• initiate a reconstruct read corresponding to a given read request directed to a particular storage device of the plurality of storage devices, in response to determining the particular storage device is exhibiting a non-error related relatively slow read response.