Patent ID: 7467329

Claim:
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; 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.