Patent ID: 8682867

Claim:
A system comprising: a data storage device for storing one or more storage volumes; and a processor and instructions stored in a memory, the instructions executed by the processor to perform operations comprising: associating an indicator with a data set on the one or more storage volumes, wherein the indicator is in a first state indicating that the data set is accessible; storing the indicator associated with the data set in a data set descriptor record, wherein the data set descriptor record is stored in at least one mapping of the one or more storage volumes; receiving a request to delete the data set; changing the indicator to a second state indicating that the data set is inaccessible in response to the request to delete the data set, with the proviso that the data set is unchanged; preferentially preserving data sets whose indicator has been changed to the second state according to one or more preservation priority criteria, the preservation priority criteria comprising at least: a priority value assigned thereto, wherein data sets whose indicator has more recently been changed to the second state are preserved over data sets whose indicator has been changed to the second state less recently in a first-in-first-out (FIFO) basis in response to a request to store a second data set to the one or more storage volumes on determining an insufficient amount of free space is available on the one or more storage volumes to store the second data set; receiving a request to restore the deleted data set; and restoring the indicator from the second state to the first state in response to the request to restore the deleted data set.