System and program for replicating a file

Abstract

Provided are a method, system, and program for replicating a file. A file is copied to a target storage file system stored as a base file. A reference file comprising the copied file is generated at a local storage. An update is applied to the file at the local storage. A delta file is generated indicating differences between the updated file at the local storage and the reference file. A file system command is used to transmit the delta file to the target storage file system store to store in a directory of the target storage file system, wherein the file in the local storage is replicated at the target storage by a combination of the base file and the delta file.

1 . A system in communication with a target storage file system having at least one directory, comprising:
 a local storage;   a processor in communication with the local storage;   a computer readable medium including code executed by the processor to perform operations, the operations comprising:   copying a file in the local storage subject to replication to the target storage file system to store as a base file in the target storage file system;   generating a reference file comprising a copy of the file subject to replication that is copied to the target storage file system;   applying an update to the file subject to replication at the local storage to generate an updated file at the local storage;   generating a delta file indicating differences between the updated file at the local storage and the reference file;   generating a code identifying the reference file;   using a file system command to transmit the delta file to the target storage file system to store in one directory of the target storage file system;   receiving a replication request to replicate the updated file from the delta file in the target storage file system;   using the code to determine whether the base file at the target storage file system matches the reference file at the local storage in response to the replication request; and   replicating the updated file from a combination of the base file and the delta file stored in the target storage in response to determining that the base file matches the reference file.   
   
   
       2 . The system of  claim 1 , wherein the base file and delta file are stored in a common directory in the target storage file system. 
   
   
       3 . The system of  claim 2 , wherein the delta file is stored in a predetermined directory location relative to the base file. 
   
   
       4 . The system of  claim 1 , wherein the delta file has a file name including a file name of the base file and includes an extension indicating a delta file type. 
   
   
       5 . The system of  claim 1 , wherein a file name of the delta file indicates a file size of the reference file on the local storage combined with the differences indicated in the delta file. 
   
   
       6 . The system of  claim 1 , wherein a file name of the delta file indicates the code identifying the reference file to which the delta applies. 
   
   
       7 . The system of  claim 1 , wherein the code comprises a checksum value calculated from the reference file and wherein using the code to determine whether the base file at the target storage file system matches the reference file comprises:
 calculating a checksum value from the base file in the target storage file system; and   comparing the checksums calculated from the reference file system and the base file to determine whether they match.   
   
   
       8 . An article of manufacture comprises a computer readable storage medium including code that when executed by a processor performs operations to communicate with a target storage file system and a local storage and to further perform operations comprising:
 copying a file in the local storage subject to replication to the target storage file system to store as a base file in the target storage file system;   generating a reference file comprising a copy of the file subject to replication that is copied to the target storage file system;   applying an update to the file subject to replication at the local storage to generate an updated file at the local storage;   generating a delta file indicating differences between the updated file at the local storage and the reference file;   generating a code identifying the reference file;   using a file system command to transmit the delta file to the target storage file system to store in a directory of the target storage file system;   receiving a replication request to replicate the updated file from the delta file in the target storage file system;   using the code to determine whether the base file at the target storage file system matches the reference file at the local storage in response to the replication request; and   replicating the updated file from a combination of the base file and the delta file stored in the target storage in response to determining that the base file matches the reference file.   
   
   
       9 . The article of manufacture of  claim 8 , wherein the base file and delta file are stored in a common directory in the target storage file system. 
   
   
       10 . The article of manufacture of  claim 9 , wherein the delta file is stored in a predetermined directory location relative to the base file. 
   
   
       11 . The article of manufacture of  claim 8 , wherein the delta file has a file name including a file name of the base file and includes an extension indicating a delta file type. 
   
   
       12 . The article of manufacture of  claim 8 , a file name of the delta file comprises a file size of the reference file on the local storage combined with the differences indicated in the delta file. 
   
   
       13 . The article of manufacture of  claim 8 , wherein a file name of the delta file indicates the code identifying the reference file to which the delta applies. 
   
   
       14 . The article of manufacture of  claim 8 , wherein the code comprises a checksum value calculated from the reference file and wherein using the code to determine whether the base file at the target storage file system matches the reference file comprises:
 calculating a checksum value from the base file in the target storage file system; and   comparing the checksums calculated from the reference file system and the base file to determine whether they match.