Log for selective management of specific address in a shadow storage system
First Claim
1. A method of managing data stored in a shadow set of storage media comprising a first storage medium and a second storage medium each accessible by a plurality of data processing devices, said method comprising the steps of:
- A. maintaining a log of information associated with write commands received from the data processing devices, comprising the steps of;
2 Assignments
0 Petitions
Accused Products
Abstract
A log for managing data in a shadow set of storage media includes a system for maintaining a log of address information associated with at least one write command received from one of a plurality of data processing devices. The system for maintaining a log of address information includes a device for receiving a write command from a data processing device, a device which writes data associated with the write command in a section of one of the storage media, and a device which writes address information in a log indicative of the location of that section. A device is provided which then implements a management operation on data stored on one of the storage media in accordance with the address information stored in the log.
-
Citations
20 Claims
-
1. A method of managing data stored in a shadow set of storage media comprising a first storage medium and a second storage medium each accessible by a plurality of data processing devices, said method comprising the steps of:
A. maintaining a log of information associated with write commands received from the data processing devices, comprising the steps of; - View Dependent Claims (4, 6, 7, 8, 9, 10, 11, 13, 14, 16, 17, 18, 19, 20)
-
2. receiving a first write command from one of the data processing devices directed to said first storage medium, said first write command including data and first address information;
-
2. writing said data to a location in said first storage medium determined by said first address information; 3. issuing an end message indicative of whether the step of writing to said first storage medium was completed successfully; 4. writing said first address information to said log; 5. receiving a second write command from said one of the data processing devices directed to said second storage medium, said second write command including said data and second address information; 6. writing said data to a location in said second storage medium determined by said second address information; 7. issuing an end message indicating whether the step of writing to said second storage medium was completed successfully; and - View Dependent Claims (5)
-
-
3. writing said second address information to said log;
- and
B. implementing a management operation on only locations in the shadow set of said storage media indicated by address information in said log to make data in said first storage medium identical to data stored in corresponding locations in said second storage medium when an end message is issued indicating a write operation to one of the first and second storage media was not completed successfully.
- and
-
12. An apparatus for managing data stored in a shadow set of storage media comprising a first storage medium and a second storage medium each accessible by a plurality of data processing devices, said apparatus comprising:
means for maintaining a log of information associated with write commands received from the data processing devices, said means for maintaining comprising; means for receiving a first and a second write command from one of the data processing devices said first write command including data and first address information, said second write command including said data and second address information; means for writing said data to a location in said first storage medium determined by said first address information and for writing said data to a location in said second storage medium determined by said second address information; means for issuing an end message indicating whether a write operation to one of said first and second storage media was completed successfully; and means for writing said first and second address information to said log; and means for implementing a management operation on only locations in the shadow set of said storage media indicated by address information in said log to make data in said first storage medium identical to data stored in corresponding locations in said second storage medium when an end message is issued indicating a write operation to one of the first and second storage media was not completed successfully. - View Dependent Claims (15)
Specification