Method and system for sidefile status polling in a time zero backup copy process

Abstract

A method and system are disclosed for enhanced efficiency of backup copying of designated datasets stored within a plurality of storage devices coupled to the data processing system via a storage subsystem control unit having subsystem memory therein. Application execution within the data processing system is temporarily suspended long enough to form a dataset logical-to-physical system address concordance to be utilized to administer copying of the designated dataset. Thereafter, application initiated updates to uncopied portions of the designated datasets are temporarily deferred until sidefiles of the affected portions of the designated datasets are written to subsystem memory. The updates are then written to the storage subsystem. Portions of the designated datasets are then accessed and copied from the storage subsystem on a scheduled or opportunistic basis utilizing selected data retrieval command sequences. A sidefile status query is appended to selected data retrieval command sequences and the presence of data within the subsystem memory is determined without the necessity of additional communications between the data processing system and the storage subsystem. The sidefiles are then accessed and copied. Copied portions of the designated datasets and sidefiles are then copied to alternate storage locations in a backup copy order defined by the address concordance.

We claim:  
     
       1. A method in a data processing system for enhanced efficiency of backup copying of designated datasets stored within a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having subsystem memory therein, said method comprising the steps of: 
       forming a dataset logical-to-physical system address concordance for said designated datasets to be utilized to administer copying of said designated datasets;  
       processing at said storage subsystem any application initiated update to uncopied portions of said designated datasets by temporarily deferring said updates, writing sidefiles of said designated datasets or portions thereof affected by said update to said subsystem memory and thereafter writing said updates to said storage subsystem;  
       accessing and copying said designated datasets within said storage subsystem on a scheduled or opportunistic basis by issuing data retrieval command sequences from said data processing system to said storage subsystems;  
       periodically appending a sidefile status query to a data retrieval command sequence wherein a determination of data presence within said subsystem memory may be accomplished; and  
       selectively accessing and copying said sidefiles in response to a determination of data presence within said subsystem memory.  
     
     
       2. The method in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  1 , further including the step of temporarily suspending application execution within said data processing system prior to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       3. The method in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  2 , further including the step of resuming application execution within said data processing system subsequent to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       4. The method in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  1 , further including the step of writing said copied designated datasets and sidefiles to an alternate storage location in a backup copy order specified by said address concordance. 
     
     
       5. A data processing system for enhanced efficiency of backup copying of designated datasets stored within a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having subsystem memory therein, said data processing system comprising: 
       means for forming a dataset logical-to-physical system address concordance for said designated datasets to be utilized to administer copying of said designated datasets;  
       means for processing at said storage subsystem any application initiated update to uncopied portions of said designated datasets by temporarily deferring said updates, writing sidefiles of said designated datasets or portions thereof affected by said update to said subsystem memory and thereafter writing said updates to said storage subsystem;  
       means for accessing and copying said designated datasets within said storage subsystem on a scheduled or opportunistic basis by issuing data retrieval command sequences from said data processing system to said storage subsystems;  
       means for periodically appending a sidefile status query to a data retrieval command sequence wherein a determination of data presence within said subsystem memory may be accomplished; and  
       means for selectively accessing and copying said sidefiles in response to a determination of data presence within said subsystem memory.  
     
     
       6. The data processing system for enhanced efficiency of backup copying of designated datasets according to claim  5 , further including means for temporarily suspending application execution within said data processing system prior to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       7. The data processing system for enhanced efficiency of backup copying of designated datasets according to claim  6 , further including means for resuming application execution within said data processing system subsequent to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       8. The data processing system for enhanced efficiency of backup copying of designated datasets according to claim  5 , further including means for writing said copied designated datasets and sidefiles to an alternate storage location in a backup copy order defined by said address concordance. 
     
     
       9. A method in a data processing system for enhanced efficiency of backup copying of designated datasets stored within a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having subsystem memory therein, said method comprising the steps of: 
       forming a dataset logical-to-physical system address concordance for said designated datasets to be utilized to administer copying of said designated datasets;  
       processing at said storage subsystem any application initiated updated to uncopied portions of said designated datasets by temporarily deferring said updates, writing sidefiles of said designated datasets or portions thereof affected by said update to said subsystem memory and thereafter writing said updates to said storage subsystem;  
       accessing and copying said designated datasets within said storage subsystem on a scheduled or opportunistic basis by issuing data retrieval command sequences from said data processing system to said storage subsystems;  
       periodically issuing a sidefile status query to determine the status of data within said subsystem memory; and  
       selectively accessing and copying said sidefiles in response to a determination of data presence within said subsystem memory.  
     
     
       10. The method in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  9 , further including the step of temporarily suspending application execution within said data processing system prior to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       11. The method in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  10 , further including the step of resuming application execution within said data processing system subsequent to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       12. A data processing system for enhanced efficiency of backup copying of designated datasets stored within a storage subsystem comprising a plurality of storage devices which are coupled to said data processing system via a storage device control unit having subsystem memory therein, said data processing system comprising: 
       means for forming a dataset logical-to-physical system address concordance for said designated datasets to be utilized to administer copying of said designated datasets;  
       means for processing at said storage subsystem any application initiated update to uncopied portions of said designated datasets by temporarily deferring said updates, writing sidefiles of said designated datasets or portions thereof affected by said update to said subsystem memory and thereafter writing said updates to said storage subsystem;  
       means for accessing and copying said designated datasets within said storage subsystem on a scheduled or opportunistic basis by issuing data retrieval command sequences from said data processing system to said storage subsystems;  
       means for periodically issuing a sidefile status query to determine the status of data within said subsystem memory; and  
       means for selectively accessing and copying said sidefiles in response to a determination of data presence within said subsystem memory.  
     
     
       13. The data processing system for enhanced efficiency of backup copying of designated datasets according to claim  12 , further including means for temporarily suspending application execution within said data processing system prior to forming said dataset logical-to-physical system address concordance for said designated datasets. 
     
     
       14. A computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets stored within a storage subsystem coupled to said data processing system via a storage device control unit having subsystem memory therein, said product comprising: 
         instruction means for forming a dataset logical - to - physical system address concordance for said designated datasets to be utilized to administer copying of said designated datasets;    
       
         instruction means for processing at said storage subsystem any application initiated update to uncopied portions of said designated datasets by temporarily deferring said updates, writing sidefiles of said designated datasets or portions thereof affected by said update to said subsystem memory and thereafter writing said updates to said storage subsystem;  
       
       
         instruction means for accessing and copying said designated datasets within said storage subsystem on a scheduled or opportunistic basis by issuing data retrieval command sequences from said data processing system to said storage subsystem;  
       
       
         instruction means for periodically appending a sidefile status query to a data retrieval command sequence wherein a determination of data presence within said subsystem memory may be accomplished; and  
       
       
         instruction means for selectively accessing and copying said sidefiles in response to a determination of data presence within said subsystem memory. 
       
     
     
       15. The computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  14 , further comprising instruction means for temporarily suspending application execution within said data processing system prior to forming said dataset logical- to - physical system address concordance for said designated datasets.   
     
     
       16. The computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  15 , further comprising instruction means for resuming application execution within said data processing system subsequent to forming said dataset logical- to - physical system address concordance for said designated datasets.   
     
     
       17. The computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  14 , further comprising instruction means for writing said copier designated datasets and sidefiles to an alternate storage location in a backup copy order specified by said address concordance. 
     
     
       18. A computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets stored within a storage subsystem coupled to said data processing system via a storage device control unit having subsystem memory therein, said product comprising: 
         instruction means for forming a dataset logical - to - physical system address concordance for said designated datasets to be utilized to administer copying of said designated datasets;    
       
         instruction means for processing at said storage subsystem any application initiated update to uncopied portions of said designated datasets by temporarily deferring said updates, writing sidefiles of said designated datasets or portions thereof affected by said update to said subsystem memory and thereafter writing said updates to said storage subsystem;  
       
       
         instruction means for accessing and copying said designated datasets within said storage subsystem on a scheduled or opportunistic basis by issuing data retrieval command sequences from said data processing system to said storage subsystem;  
       
       
         instruction means for periodically issuing a sidefile status query to determine the status of data within said subsystem memory; and  
       
       
         instruction means for selectively accessing and copying said sidefiles in response to a determination of data presence within said subsystem memory. 
       
     
     
       19. The computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  18 , further comprising instruction means for temporarily suspending application execution within said data processing system prior to forming said dataset logical- to - physical system address concordance for said designated datasets.   
     
     
       20. The computer program product for use in a data processing system for enhanced efficiency of backup copying of designated datasets according to claim  19 , further comprising instruction means for resuming application execution within said data processing system subsequent to forming said dataset logical- to - physical system address concordance for said designated datasets.