Method a source storage device to send a source file and a clone file of the source file to a backup storage device, a source storage device and a backup storage device

A method for a backup storage device to backup a source file and a clone file of the source file, the method comprising:

• receiving, by a processor included in the backup storage device, a data block of the source file from a source storage device, wherein the backup storage device includes the processor and one or more disks for storing a plurality of files;
• storing, by the processor included in the backup storage device, the data block as part of a target file, wherein the target file includes a first block pointer pointing to the data block;
• receiving, by the processor included in the backup storage device from the source storage device, a clone creating request including a source file ID of the source file and an ID of the clone file of the source file;
• allocating, by the processor included in the backup storage device, a target file ID for the target file, wherein the target file ID is identical to the source file ID;
• creating, by the processor included in the backup storage device, a clone file of the target file based upon the source file ID, wherein the clone file of the target file includes a second block pointer pointing to the data block, wherein the step of creating the clone file of the target file based upon the source file ID comprises:
• determining that the clone file of the target file needs to be created based on the source file ID;
• and
• creating the clone file of the target file;
• and
• allocating an ID of the clone file of the target file, wherein the ID of the clone file of the target file is identical to the ID of the clone file of the source file.

A source storage device for sending data to a backup storage device, the source storage device comprising:

• one or more disks for storing files, wherein a source file includes a data block and a first block pointer pointing to the data block, and a clone file of the source file includes a second block pointer pointing to the data block;
• and
• a processor configured to:
• send the data block to the backup storage device to be stored as a target file;
• determine that the source file is associated with the clone file by searching a cloning recorder with a source file ID of the source file, wherein the cloning recorder includes IDs of files each associated with an ID of a corresponding clone file;
• based upon the determining, send a clone creating request including the source file ID and an ID of the clone file of the source file to the backup storage device to instruct the backup storage device to create a clone file of the target file;
• receive a message in response to the clone creating request, wherein the message includes an ID of the clone file of the target file, and wherein the ID of the clone file of the target file is identical to the ID of clone file of the source file;
• determine that the source file has been updated after the clone file of the source file is created, wherein first update data is used to update the source file and is written into the source storage device after the clone file of the source file in the source storage device is created;
• and
• after receiving the message in response to the clone creating request, send the first update data to the backup storage device to be stored on the backup storage device, wherein sending the first update data to the backup storage device causes the backup storage device to:
• record, by a log program, a log of the first update data and write the log into a log area, wherein the log includes an offset within the target file and a size of the first update data;
• based on the offset within the target file and the size of the first update data, determine which block of the target file corresponds to a block to be replaced by the first update data;
• and
• redirect a data pointer pointing to the block to be replaced to a block corresponding to the first update data stored on backup storage device.

A backup storage device for backing up a source file and a clone file of the source file, the backup storage device comprising:

• one or more disks for storing a plurality of files;
• and
• a processor configured to:
• receive a data block of the source file from the source storage device;
• store the data block as part of a target file, wherein the target file includes a first block pointer pointing to the data block;
• receive, from the source storage device, a clone creating request including a source file ID of the source file and an ID of the clone file of the source file;
• allocate a target file ID for the target file, wherein the target file ID is identical to the source file ID;
• create a clone file of the target file based upon the source file ID, wherein the clone file of the target file includes a second block pointer pointing to the data block, wherein creating the clone file of the target file based upon the source file ID comprises:
• determining that the clone file of the target file needs to be created based on the source file ID;
• and
• creating the clone file of the target file;
• and
• allocate an ID of the clone file of the target file, wherein the ID of the clone file of the target file is identical to the ID of the clone file of the source file.