Method of moving files in hierarchical storage system

A computer system for moving files from an HDD to a tape drive in a hierarchical storage system, the computer system comprising:

• one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage devices, and program instructions stored on at least one of the one or more storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, wherein the computer system is capable of performing a method comprising the steps of:
• obtaining, from the tape drive, a data size available to be sequentially written in a wrap of a tape within the tape drive;
• receiving, from the tape drive, an indication whether the wrap extends in a trailing end direction of the tape or in a leading end direction of the tape opposite to the trailing end direction at a time of accessing the wrap;
• extracting, from a plurality of files in the HDD, one or more files not stored in the tape drive in an ascending order of data size;
• estimating a physical size needed for writing the extracted one or more files in the tape drive;
• in response to the estimated physical size not exceeding the data size available to be sequentially written in the tape drive, selecting the extracted one or more files as files to be written to the tape drive;
• and
• in response to the wrap extending from the leading end direction of the tape to the trailing end direction of the tape, writing the extracted one or more files in an ascending order of data size from the leading end direction to the trailing end direction.

A computer program product for moving files from an HDD to a tape drive in a hierarchical storage system, the computer program product comprising:

• a computer readable non-transitory article of manufacture tangibly embodying computer readable instructions which, when executed, cause a computer to carry out a method comprising the steps of:
• obtaining, from the tape drive, a data size available to be sequentially written in a wrap of a tape within the tape drive;
• receiving, from the tape drive, an indication whether the wrap extends in a trailing end direction of the tape or in a leading end direction of the tape opposite to the trailing end direction at a time of accessing the wrap;
• extracting, from a plurality of files in the HDD, one or more files not stored in the tape drive in an ascending order of data size;
• estimating a physical size needed for writing the extracted one or more files in the tape drive;
• in response to the estimated physical size not exceeding the data size available to be sequentially written in the tape drive, selecting the extracted one or more files as files to be written to the tape drive;
• and
• in response to the wrap extending from the leading end direction of the tape to the trailing end direction of the tape, writing the extracted one or more files in an ascending order of data size from the leading end direction to the trailing end direction.