Synchronized mirrored data in a data storage device

Abstract

A data storage device mirrors data on a data storage medium. The multiple instances of data are synchronized in order to optimize performance of the reading and writing, and the integrity of the data. Preferably, a data storage device is allowed to defer writing multiple copies of data until a more advantageous time.

1. A method comprising the steps of:
 receiving a command to retrieve data associated with mirrored data of a data storage medium in a data storage device; 
 determining whether the retrieve command is associated with synchronized or unsynchronized data; 
 inserting at least one retrieve sub-request from the retrieve command into a scheduling pool; 
 scheduling one of the retrieve sub-requests; and 
 removing remaining sub-requests from the scheduling pool. 
 
     
     
       2. The method of  claim 1 , and further comprising if the retrieve command is associated with unsynchronized data:
 synchronizing data. 
 
     
     
       3. The method of  claim 2 , wherein the synchronizing data further comprises the steps of:
 completing stores of entries in a data structure indicating which store requests have not been completed that are related to the command. 
 
     
     
       4. The method of  claim 1 , if the retrieve command is associated with unsynchronized data:
 retrieving most recently stored data. 
 
     
     
       5. A data storage device comprising:
 a data storage medium comprising mirrored data; 
 an input for receiving a retrieve command associated with the mirrored data; and 
 a controller, which determines whether the retrieve command is associated with synchronized or unsynchronized data, inserts at least one retrieve sub-request from the retrieve command into a scheduling pool, schedules one of the retrieve sub-requests, and removes remaining sub-requests from the scheduling pool. 
 
     
     
       6. The data storage device of  claim 5  and further comprising a synchronizer, which synchronizes the data if the retrieve command is associated with unsynchronized data. 
     
     
       7. The data storage device of  claim 6 , wherein the controller is further adapted to complete stores of entries in a data structure indicating which store requests have not been completed that are related to the command. 
     
     
       8. The data storage device of  claim 5 , the controller is adapted to retrieve most recently stored data if the retrieve command is associated with unsynchronized data. 
     
     
       9. A circuit-based method comprising:
 in response to a command that prompts execution of circuit-based logic to retrieve data associated with mirrored data of a data storage medium in a data storage device, and to an indication of whether the retrieve command is associated with synchronized or unsynchronized data, using the circuit-based logic to facilitate
 inserting at least one retrieve sub-request from the retrieve command into a scheduling pool; 
 scheduling one of the retrieve sub-requests; and 
 removing remaining sub-requests from the scheduling pool. 
   
     
     
       10. The method of claim 9, and further comprising if the retrieve command is associated with unsynchronized data:
 synchronizing data.   
     
     
       11. The method of claim 10, wherein the synchronizing data further comprises the steps of:
 completing stores of entries in a data structure indicating which store requests have not been completed that are related to the command.   
     
     
       12. The method of claim 11, if the retrieve command is associated with unsynchronized data:
 retrieving most recently stored data.   
     
     
       13. The method of claim 9, and further comprising if the retrieve command is associated with unsynchronized data, then synchronizing data, and therein managing a destructive condition associated with a data storage device that is configured to store the mirrored data. 
     
     
       14. The method of claim 9, and further comprising:
 managing a destructive condition associated with a data storage device that is configured to store the mirrored data.