Patent ID: 7353351
Filing Date: 2008-04-01
Classification: G06F,Y10S

Abstract:
1. In a data storage environment having a first volume of data denominated as the source being stored on a data storage system, and a second volume of data denominated as a clone and which has data content that is a copy of the data content of the source being stored on the data storage system or on another data storage system, a method, operable on a computer system, for managing data content during a restoration of the source, the method comprising the steps of: restoring the source by copying data content from the clone to overwrite the data content of the source, allowing host reads and writes to the source in a copy-on-demand process; if preserving the data content of the clone is selected, then not allowing the data content of the clone to be overwritten by host writes during the restoring step; and if preserving the data content of the clone is not selected, then during the restoring step overwriting the data contents of the clone that is providing said clone data and determining extents of the source affected by any host write request; and if any extents affected by the host write request are involved during the restoring step and preserving is not selected, allowing the host writes to be processed as soon as the required extents have been copied from the clone to the source, and setting an indicator to indicate that the extents need to be re-copied.