Method of estimating storage system reliability

A computer-implemented method of estimating storage system reliability comprising the steps of:

• modeling a storage system design in operation under a workload by employing a hierarchical model to determine location of retrieval points, the hierarchical model having levels corresponding to each of a primary storage location and a plurality of secondary storage locations, the primary and secondary storage locations serving as sources for retrieval points of successively lower levels of the hierarchical model, and the retrieval points providing sources for primary storage recovery for a plurality of failure scenarios;
• and
• for a particular failure scenario:
• receiving a target recovery time, which is a point-in-time to which restoration of data is desired;
• finding a most recent retrieval point relative to the target recovery time that is available for recovery which includes considering the secondary storage locations among the plurality of secondary storage locations having successively older retention periods for the retrieval points until the most recent retrieval point is found;
• and
• determining a difference between the target recovery time and a retrieval point creation time for the most recent retrieval point, the difference indicating a data loss time period.

A computer readable medium comprising computer code which when executed implements a method of estimating storage system reliability, the method of estimating storage system reliability comprising the steps of:

• modeling a storage system design in operation under a workload by employing a hierarchical model to determine location of retrieval points, the hierarchical model having levels corresponding to each of a primary storage location and a plurality of secondary storage locations, the primary and secondary storage locations serving as sources for retrieval points of successively lower levels of the hierarchical model, and the retrieval points providing sources for primary storage recovery for a plurality of failure scenarios;
• and
• for a particular failure scenario:
• receiving a target recovery time, which is a point-in-time to which restoration of data is desired;
• determining a range of times of the retrieval points for each of the secondary storage locations;
• finding a most recent retrieval point relative to the target recovery time that is available for recovery, the most recent retrieval point being at a secondary storage location among the plurality of secondary storage locations;
• and
• determining a difference between the target recovery time and a retrieval point creation time for the most recent retrieval point, the difference indicating a data loss time period.

A computer readable medium comprising computer code which when executed implements a method of estimating storage system reliability, the method of estimating storage system reliability comprising the steps of:

• modeling a storage system design in operation under a workload by employing a hierarchical model to determine location of retrieval points, the hierarchical model having levels corresponding to each of a primary storage location and a plurality of secondary storage locations, the primary and secondary storage locations serving as sources for retrieval points of successively lower levels of the hierarchical model, and the retrieval points providing sources for primary storage recovery for a plurality of failure scenarios;
• and
• for a particular failure scenario:
• receiving a target recovery time, which is a point-in-time to which restoration of data is desired;
• finding a most recent retrieval point relative to the target recovery time that is available for recovery which includes considering the secondary storage locations among the plurality of secondary storage locations having successively older retention periods for the retrieval points until the most recent retrieval point is found;
• and
• determining a difference between the target recovery time and a retrieval point creation time for the most recent retrieval point, the difference indicating a data loss time period.