Techniques for determining the extent of data loss as a result of a data storage system failure
AssigneeInternational Business Machines Corporation
InventorsDeborah A. Messing, Itzhack Goldberg, Harry R. McGregor, Christopher B. Moore
Life of this patent
Estimating the term…
Abstract
A technique for operating a data storage system includes generating information that identifies data that is currently stored in a write cache of the data storage system. The information is stored in a data structure associated with the data storage system. In response to a failure of the data storage system, the information in the data structure is accessed to identify the data that was lost in the failure.
Claims20
A method of operating a data storage system including a non-volatile storage device and write cache that temporarily buffers data to be written from the write cache into the non-volatile storage device, the method comprising:
- generating, by a controller, information that identifies data that is currently stored in the write cache of the data storage system;
- storing, by the controller in a data structure associated with the data storage system and separate from the write cache, the information that identifies the data stored in the write cache but not the data itself;
- and
- based on detecting a failure of the data storage system that causes the data in the write cache to be lost, accessing, by the controller, the information in the data structure and, based on the information accessed from the data structure, identifying the data stored in the write cache that was lost as a result of the failure.
A data storage system, comprising:
- a non-volatile memory (NVM) array;
- a write cache coupled to the NVM array;
- and
- a controller coupled to the NVM array, wherein the controller is configured to:
- generate information that identifies data that is currently stored in the write cache of the data storage system;
- store the information that identifies the data, but not the data itself in a data structure associated with the data storage system and separate from the write cache;
- and
- based on detecting a failure of the data storage system that causes the data in the write cache to be lost, access the information in the data structure and based on the information accessed from the data structure, identify the data stored in the write cache that was lost as a result of the failure.
A computer program product, the computer program product comprising a computer readable storage medium having program instructions embodied therein, the program instructions executable by a controller of a data storage system including a non-volatile storage device and a memory cache, to cause the controller to:
- generate information that identifies data that is currently stored in the write cache of the data storage system;
- store the information that identifies the data, but not the data itself in a data structure associated with the data storage system and separate from the write cache;
- and
- based on detecting a failure of the data storage system that causes the data in the write cache to be lost, access the information in the data structure and, based on the information accessed from the data structure, identify the data stored in the write cache that was lost as a result of the failure.
Dependencies are inferred from the claim text.