Dynamic tape storage device data buffer

Patent metadata

Field	Value
Publication number	US-12032825-B2
Application number	US-202318143691-A
Country	US
Kind code	B2
Filing date	May 5, 2023
Priority date	Feb 25, 2021
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A computer-implemented method for altering a current position in a Data Partition of a tape at which the tape transitions to a DATA_FULL state is disclosed. The computer-implemented method includes determining a size of a last Index appended to the Data Partition of the tape. The computer-implemented method further includes altering, based on the size of the last Index appended to the Data Partition of the tape, the current position in the Data Partition of the tape at which the tape transitions to DATA_FULL state to a new position in the DATA Partition of the tape at which the tape transitions to the DATA_FULL state, wherein the DATA_FULL state is a state on the tape in which only metadata write operations are permitted in the Data Partition.

First claim

What is claimed is:

1. A computer-implemented method for altering a current position in a Data Partition of a tape at which the tape transitions to a DATA_FULL state, comprising:
determining a size of a last-written Index appended to the Data Partition of the tape; and
altering, based on the size of the last-written Index appended to the Data Partition of the tape, the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to a new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state, wherein the DATA_FULL state is a state on the tape in which only metadata write operations are permitted in the Data Partition.

2. The computer-implemented method of claim 1 , wherein the DATA_FULL state occurs in response to a tape head reaching an end of a programmable early warning zone (PEWZ) in the Data Partition of the tape during a file operation.

3. The computer-implemented method of claim 1 , wherein altering the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to the new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state further includes altering a position of a programmable early warning zone (PEWZ) in the Data Partition of the tape.

4. The computer-implemented method of claim 3 , wherein altering the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to the new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state further includes altering a size of a buffer positioned subsequent to the PEWZ in the Data Partition of the tape, wherein only metadata write operations are permitted in the buffer.

5. The computer-implemented method of 1 , wherein the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state is moved towards an end of a writable area of the Data Partition of the tape if the size of the last-written Index appended to the Data Partition of the tape is less than a storage area of a buffer located between the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state and the end of the writable area of the Data Partition of the tape.

6. The computer-implemented method of claim 1 , wherein the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state is moved away from an end of a writeable area of the Data Partition of the tape if the size of the last-written Index appended to the Data Partition of the tape is greater than a storage area of a buffer located between the current position on the tape at which the tape transitions to the DATA_FULL state and the end of the writable area of the Data Partition of the tape.

7. A computer-implemented method for altering a current position in a Data Partition of a tape at which the tape transitions to a DATA_FULL state, comprising:
determining an average size of a predetermined number of previous Indexes appended to the Data Partition of the tape; and
altering, based on the average size of the predetermined number of previous Indexes appended to the Data Partition of the tape, the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to a new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state, wherein the DATA_FULL state is a state on the tape in which only metadata write operations are permitted in the Data Partition.

8. The computer-implemented method of claim 1 , wherein the DATA_FULL state occurs in response to a tape head reaching an end of a programmable early warning zone (PEWZ) in the Data Partition of the tape during a file operation.

9. The computer-implemented method of claim 1 , wherein altering the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to the new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state further includes altering a position of a programmable early warning zone (PEWZ) in the Data Partition of the tape.

10. The computer-implemented method of claim 9 , wherein altering the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to the new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state further includes altering a size of a buffer positioned subsequent to the PEWZ in the Data Partition of the tape, wherein only metadata write operations are permitted in the buffer.

11. The computer-implemented method of 7 , wherein the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state is moved towards an end of a writable area of the Data Partition of the tape if the average size of the predetermined number of previous Indexes appended to the Data Partition of the tape is less than a storage area of a buffer located between the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state and the end of the writable area of the Data Partition of the tape.

12. The computer-implemented method of claim 7 , wherein the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state is moved away from an end of a writeable area of the Data Partition of the tape if the average size of the predetermined number of previous Indexes appended to the Data Partition of the tape is greater than a storage area of a buffer located between the current position on the tape at which the tape transitions to the DATA_FULL state and the end of the writable area of the Data Partition of the tape.

13. A computer-implemented method for altering a current position in a Data Partition of a tape at which the tape transitions to a DATA_FULL state, comprising:
determining an average size of all previous Indexes appended to the Data Partition of the tape; and
altering, based on the average size of all the previous Indexes appended to the Data Partition of the tape, the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to a new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state, wherein the DATA_FULL state is a state on the tape in which only metadata write operations are permitted in the Data Partition.

14. The computer-implemented method of claim 3 , wherein the DATA_FULL state occurs in response to a tape head reaching an end of a programmable early warning zone (PEWZ) in the Data Partition of the tape during a file operation.

15. The computer-implemented method of claim 13 , wherein altering the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to the new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state further includes altering a position of a programmable early warning zone (PEWZ) in the Data Partition of the tape.

16. The computer-implemented method of claim 15 , wherein altering the current position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state to the new position in the Data Partition of the tape at which the tape transitions to the DATA_FULL state further includes altering a size of a buffer positioned subsequent to the PEWZ in the Data Partition of the tape, wherein only metadata write operations are permitted i

Assignees

• IBM

Inventors

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

Classifications

• G06F3/0631

  by allocating resources to storage systems · CPC title

• G06F3/0656

  Data buffering arrangements · CPC title

• G06F3/0682 Primary

  Tape device · CPC title

• G11B5/00817

  on longitudinal tracks only, e.g. for serpentine format recording · CPC title

• G06F3/0644

  Management of space entities, e.g. partitions, extents, pools · CPC title