Tape image reclaim in hierarchical storage systems

Patent metadata

Field	Value
Publication number	US-11221989-B2
Application number	US-201816050225-A
Country	US
Kind code	B2
Filing date	Jul 31, 2018
Priority date	Jul 31, 2018
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A computer-implemented method for performing a storage reclaim on a storage device includes generating a second tape image on a first storage device. The computer-implemented method further includes copying metadata associated with a first data extent of a valid file from a first index partition of a first tape image to a second index partition of the second tape image. The computer-implemented method further includes copying file data associated with the first data extent from a first data partition of the first tape image to a second data partition of the second tape image. The computer-implemented method further includes adjusting metadata associated with the file data of the first data extent copied to the second data partition of the second tape image. The computer-implemented method further includes releasing a storage area corresponding to the first data extent of the valid file included in the first tape image.

First claim

What is claimed is:

1. A computer-implemented method for performing a storage reclaim for tape images stored on a disk drive, the computer-implemented method comprising:
generating a second tape image on the disk drive, wherein the second tape image is void of any data;
copying only metadata and file data associated with valid files from a first tape image stored on the disk drive to the second tape image stored on the disk drive;
reducing a number of data extents included in a data partition of the second tape image based on rearranging an order in which records of the valid files are copied from a data partition of the first tape image to respective storage blocks associated with the data partition of the second tape image; and
releasing, in response to copying only the metadata and file data associated with the valid files from the first tape image stored on the disk drive to the second tape image stored on the disk drive, the respective storage areas corresponding to an index partition and a data partition of the first tape image,
wherein a valid file is file data stored in a data partition on the disk drive that is referenced by an index partition.

2. The computer-implemented method of claim 1 , wherein copying metadata associated with the valid files includes:
copying metadata associated with each respective valid file from the index partition of the first tape image to an index partition of the second tape image on a per record basis.

3. The computer-implemented method of claim 1 , wherein copying file data associated with the valid files includes:
copying file data associated with each respective valid file from the data partition of the first tape image to the data partition of the second tape image on a per record basis.

4. The computer-implemented method of claim 1 , further comprising:
determining that a length of a last sequential record included in a data extent of a valid file copied to the data partition of the second tape image is less than a block size of a data block in which a last sequential record is stored upon;
copying file data associated with a next sequential record of the data extent of the valid file from the data partition of the first tape image to the data partition of the second tape image; and
appending the next sequential record of the data extent of the valid file to the end of the last sequential record stored on the data block.

5. The computer-implemented method of claim 1 , further comprising:
determining that a length of a final record included in a first data extent of a valid file copied to the data partition of the second tape image is less than a block size of a data block in which a last sequential record is stored upon;
copying file data associated with a first sequential record of a second data extent of the valid file from the data partition of the first tape image to the data partition of the second tape image; and
appending the first sequential record of the second data extent of the valid file to the end of the last sequential record stored on the data block.

6. The computer-implemented method of claim 1 , further comprising:
determining that a length of a record included in a data extent of a valid file of the first tape image is equal to a block size of a data block in which the record is stored upon; and
moving file data associated with the record included in the data extent of the valid file from the data partition of the first tape image to an empty data block in the data partition of the second tape image.

7. The computer-implemented method of claim 1 , further comprising:
adjusting metadata associated with the file data of the valid files copied to the data partition of the second tape image, wherein adjusting metadata includes:
adjusting a file offset of one or more of the data extents based on a number of bytes from a beginning of a valid file to a beginning of the file data included in an extent stored in the data partition of the second tape image.

8. The computer-implemented method of claim 7 , wherein adjusting metadata associated with the file data of the valid files copied to the data partition of the second tape image further includes:
adjusting a byte offset for one or more records included in each of the valid files based on a position of a record stored on a data block in the data partition of the second tape image.

9. The computer-implemented method of claim 1 , wherein the hard disk is configured as a primary storage layer in a hierarchical storage management system including the primary storage layer and a secondary storage layer.

10. The computer-implemented method of claim 1 , wherein releasing, in response to copying only the metadata and file data associated with the valid files from the first tape image stored on the disk drive to the second tape image stored on the disk drive, the respective storage areas corresponding to an index partition and a data partition of the first tape includes:
removing metadata associated with the valid files and metadata associated with invalid files stored on the index partition of the first tape image; and
removing file data associated with the valid files and file data associated with invalid files stored on the data partition of the first tape image, wherein:
an invalid file is file data in a data partition stored on the disk drive that is not referenced by an index partition.

11. A computer program product for performing a storage reclaim on a disk drive, the computer program product comprising one or more non-transitory computer readable storage media and program instructions stored on the one or more non-transitory computer readable storage media, the program instructions including instructions to:
generate a second tape image on the disk drive, wherein the second tape image is void of any data;
copy only metadata and file data associated with valid files from a first tape image stored on the disk drive to the second tape image stored on the disk drive; and
reduce a number of data extents included in a data partition of the second tape image based on rearranging an order in which records of the valid files are copied from a data artition of the first tape image to respective storage blocks associated with the data partition of the second tape image; and
release, in response to copying only the metadata and file data associated with the valid files from the first tape image stored on the hard disk to the second tape image stored on the disk drive, the respective storage areas corresponding to an index partition and a data partition of the first tape image,
wherein a valid file is file data in a data partition stored on the disk drive that is referenced by an index partition.

12. The computer program product of claim 11 , wherein the program instructions to copy metadata associated with the valid files include instructions to:
copy file data associated with each respective valid file from the index partition of the first tape image to an index partition of the second tape image on a per record basis.

13. The computer program product of claim 11 , wherein the program instructions to copy file data associated with the valid files includes instructions to:
copy file data associated with each respective valid file from the data partition of the first tape image to the data partition of the second tape image on a per record basis.

14. A computer system for accelerated data removal for performing a storage reclaim on a storage device, the computer system comprising:
one or more computer hardware processors;
one or more computer readable storage media;
computer program instructions;
the

Assignees

• IBM

Inventors

• Mitsuma Shinsuke
• Miyamura Tsuyoshi
• Itagaki Hiroshi
• Hasegawa Tohru
• Yamamoto Noriko
• Matsui Sosuke

Classifications

• G06F16/119

  Details of migration of file systems (migration mechanisms in storage systems G06F3/0647) · CPC title

• G11B5/00813 Primary

  magnetic tapes · CPC title

• G06F16/164 Primary

  File meta data generation · CPC title