Arranging data handling in a computer-implemented system in accordance with reliability ratings based on reverse predictive failure analysis in response to changes

In a RAID data storage system comprising a plurality of data storage physical entities arranged in an array to provide data storage and parity storage, a method comprising the steps of:

• assigning at least one reliability rating to various said data storage physical entities of said RAID data storage system;
• and
• using said assigned reliability ratings in accordance with reverse predictive failure analysis, to provide a designated cumulative reliability rating, said designated cumulative reliability rating is determined in accordance with the following equation:
• 1−[PAF(f+Δf,n+Δn)]=1−[PAF(f,n)+(∂PAF/∂f)*Δf+(∂PAF/∂n)*Δn],
• where:
• PAF=probability of failure of said array,
• f=probability of failure of a physical entity, and
• n=number of drives in said array.

A computer-implemented system comprising:

• a plurality of existing physical entities;
• and
• a computer-implemented data handling control implementing a method comprising the steps of:
• assigning at least one reliability rating to various said existing physical entities of said computer-implemented system;
• and
• using said assigned reliability ratings in accordance with reverse predictive failure analysis, to provide a designated cumulative reliability rating, said designated cumulative reliability rating is determined in accordance with the following equation:
• 1−[PAF(f+Δf,n+Δn)]=1−[PAF(f,n)+(∂PAF/∂f)*Δf+(∂PAF/∂n)*Δn],
• where:
• PAF=probability of failure of said computer-implemented system,
• f=probability of failure of a physical entity, and
• n=number of drives in said computer-implemented system.

A RAID data storage system comprising:

• a plurality of data storage physical entities arranged in an array to provide data storage and parity storage;
• and
• RAID management configured to:
• assign at least one reliability rating to various said data storage physical entities;
• and
• using said assigned reliability ratings in accordance with reverse predictive failure analysis, to provide a designated cumulative reliability rating, said designated cumulative reliability rating is determined in accordance with the following equation:
• 1−[PAF(f+Δf,n+Δn)]=1−[PAF(f,n)+(∂PAF/∂f)*Δf+(∂PAF/∂n)*Δn],
• where:
• PAF=probability of failure of said array,
• f=probability of failure of a physical entity, and
• n=number of drives in said array.

A computer program product for arranging data handling by at least one computer-implemented processor for a computer-implemented system comprising a plurality of existing physical entities, said computer program product comprising a non-transitory computer-usable storage medium having non-transient computer-usable program code embodied therein, comprising:

• computer-usable program code for said processor to assign at least one reliability rating to various said existing physical entities of said computer-implemented system;
• and
• computer-usable program code for said processor to use said assigned reliability ratings in accordance with reverse predictive failure analysis, to provide a designated cumulative reliability rating, said designated cumulative reliability rating is determined in accordance with the following equation:
• 1−[PAF(f+Δf,n+Δn)]=1−[PAF(f,n)+(∂PAF/∂f)*Δf+(∂PAF/∂n)*Δn],
• where:
• PAF=probability of failure of said computer-implemented system,
• f=probability of failure of a physical entity, and
• n=number of drives in said computer-implemented system.

A computer program product for arranging data handling by at least one computer-implemented processor for a RAID data storage system comprising a plurality of data storage physical entities arranged to provide data storage and parity storage, said computer program product comprising computer-usable storage medium having non-transient computer-usable program code embodied therein, comprising:

• computer-usable program code for said processor to assign at least one reliability rating to various said data storage physical entities;
• and
• computer-usable program code for said processor to use said assigned reliability ratings in accordance with reverse predictive failure analysis, to provide a designated cumulative reliability rating, said designated cumulative reliability rating is determined in accordance with the following equation:
• 1−[PAF(f+Δf,n+Δn)]=1−[PAF(f,n)+(∂PAF/∂f)*Δf+(∂PAF/∂n)*Δn],
• where:
• PAF=probability of failure of said array,
• f=probability of failure of a physical entity, and
• n=number of drives in said array.