Data writing in a file system

Patent metadata

Field	Value
Publication number	US-9671979-B2
Application number	US-201615234032-A
Country	US
Kind code	B2
Filing date	Aug 11, 2016
Priority date	Nov 9, 2015
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

In an approach for writing data on a tape using a file system, a processor receives a first write request of a first file. A processor obtains data of the first file. A processor writes the data of the first file on a tape. A processor receives a second write request of a second file prior to completion of writing the data of the first file on the tape. A processor adds information about the second file to a first list, wherein the first list includes files waiting to write. Subsequent to writing the data of the first file on the tape, a processor obtains data of the second file based on the first list. A processor writes the data of the second file after the first file on the tape.

First claim

What is claimed is:

1. A computer program product for writing data on a tape using a file system, the computer program product comprising:
one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising:
program instructions to receive a first write request of a first file;
program instructions to obtain data of the first file;
program instructions to write the data of the first file on a tape, wherein program instructions to write the data of the first file on the tape comprise:
program instructions to write a first portion of the data of the first file in a first wrap of the tape, wherein the first portion of the data of the first file is of a first predetermined length; and
program instructions to write information on a write position of the first portion of the data of the first file in a second list, wherein the second list includes information about write interrupts;

program instructions to receive a second write request of a second file prior to completion of writing the data of the first file on the tape;
program instructions to add information about the second file to a first list, wherein the first list includes files waiting to write;
subsequent to writing the data of the first file on the tape, program instructions to obtain data of the second file based on the first list;
program instructions to write the data of the second file after the first file on the tape, wherein program instructions to write the data of the second file after the first file on the tape comprise:
program instructions to write a first portion of the data of the second file after the first portion of the data of the first file in the first wrap of the tape, wherein the first portion of the data of the second file is of a second predetermined length; and
program instructions to write information on a write position of the first portion of the data of the second file in the second list;

program instructions to write a second portion of the data of the second file in a second wrap of the tape, wherein the second portion of the data of the second file is of a third predetermined length, based on the information on the write position of the first portion of the data of the second file in the second list;
program instructions to write a second portion of the data of the first file in a second wrap of the tape, wherein the second portion of the data of the first file is of a fourth predetermined length, based on the information on the write position of the first portion of the data of the first file in the second list;
program instructions to receive a third write request of a third file prior to completion of writing the data of the first file on the tape;
program instructions to add information about the third file to the first list, such that the information about the third file is of a lower priority than the information about the second file on the first list; and
subsequent to writing the second portion of data of the first file in the second wrap of the tape, program instructions to delete the information on the write position of the first portion of the data of the first file from the second list.

Assignees

• IBM

Inventors

• Hasegawa Tohru
• Itagaki Hiroshi
• Mitsuma Shinsuke
• Yamamoto Noriko
• Watanabe Terue

Classifications

• G11B20/1201

  on tapes · CPC title

• G11B20/1205

  for discontinuous data, e.g. digital information signals or computer program data · CPC title

• G11B20/1202

  with longitudinal tracks only · CPC title

• G06F3/061

  Improving I/O performance · CPC title

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title