Method of performing a high-performance backup which gains efficiency by reading input file blocks sequentially

• US 6,415,300 B1
• Filed: 07/06/1999
• Issued: 07/02/2002
• Est. Priority Date: 07/06/1999
• Status: Expired due to Term

• Current Assignee: Catalogic Software, Inc.
• Original Assignee: Syncsort Incorporated
• Inventors: Liu, Peter Chi-Hsiung
• Primary Examiner(s): Alam, Hosain T.
• Assistant Examiner(s): HWANG, JOON H
• Application Number:
  US09/347,931
• Time in Patent Office: 1,092 Days
• Field of Search: 707/200-205, 707/1-10, 709/200, 709/217-219, 711/111, 711/112, 711/114, 711/161, 711/162, 711/154
• US Class Current: 707/652
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

An improved method of performing a high-performance backup of a computer system is described, which reduces disk read time and thus gains efficiency by reading input file blocks sequentially rather than the order in which the block appear in the original files. The improved method involves reading the working directory maintained by the operating system to determine all of the blocks associated with the set of files or other data aggregations to be backed up. The data block identities so determined are sorted in accordance with their physical location on the disk, thereby providing a sequential order for reading. The data to be backed up from the random access storage device or devices is read in this sequential order, and written to the backup media. There is also stored in conjunction with the backup media a Catalog containing the names of the files in the backup set, the location of the file data blocks on the backup media, the proper ordering of the blocks in this original file, and any other desired file attribute information.

Claims

1. A method for performing a backup to specified backup media of certain data to be backed up which is stored on one or more disk or other random access data storage devices, said data to be backed up being organized in files or other data aggregations, and such device or devices having a working directory containing information on where the data comprising said files or other groups of data are physically stored on said random access storage device or devices, said method comprising:

a) prior to reading any of said data to be backed up, reading said working directory to determine all of the blocks associated with the set of files or other data aggregations for backup;

prior to reading any of said data to be backed up

b) ordering the block numbers read from said working directory, thereby determining a sequential order for reading from said random access storage device or devices the data to be backed up;

c) reading the data to be backed up from said random access storage device or devices in accordance with said determined sequential order, and writing said data to the backup media; and

d) storing on the backup media, or on other suitable media, a catalog comprising organizational information specifying where the data comprising said files or data aggregations within the backed up data set are physically stored on said backup media.

3. A method for restoring a specified file contained within a backed up data set which has been created in accordance with the methods of claims 1 or 2, further comprising:

a) searching said catalog, and extracting therefrom information specifying the physical location and order in said backup media of the data comprising said file;

b) reading data from said backup media in accordance with said extracted ordering information; and

c) restoring the data so read from said backup media to target media for such restoration, and updating the corresponding working directory information on said target media.

4. An article of manufacture comprising a data storage medium on which there has been recorded a computer program which, when executed on a suitable computer system, performs a method of claim 3.

5. A system comprising a general purpose digital computer in which there has been loaded into the appropriate memory and instruction storage areas a computer program which, when executed, performs a method of claim 3.

6. An article of manufacture comprising a data storage medium on which there has been recorded a computer program which when executed on a suitable computer system performs the methods of claims 1 or 2.

7. A system comprising a general purpose digital computer in which there has been loaded into the appropriate memory and instruction storage areas a computer program which when executed performs the methods of claims 1 or 2.

2. A method for performing a backup to specified backup media of some or all files which are stored on a disk volume, in the form of a direct access storage device such volume having a working directory containing information on where the data comprising said files are physically stored on said volume, said method comprising:

a) reading said working directory to determine the physically contiguous runs of data on said disk volume associated with said

prior to reading any of said data comprising said files to be backed up, files, and information about the location of said runs on said disk volume;

b) sorting said location information with regard to all of said runs and thereby determining the of said runs on said disk volume;

c) sequentially reading all blocks of data from said runs in accordance with said determined physical order, and writing said data to the backup media; and

d) storing on the backup media, or on other suitable media, a catalog comprising organizational information specifying where the data comprising said files or data aggregations within the backed up data set are physically stored on said backup media.