APPARATUS, SYSTEM, AND METHOD FOR READ BACK VERIFICATION OF STORED DATA

• US 20070260623A1
• Filed: 05/05/2006
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mittelholzer, Thomas, Jaquette, Glen
• Granted Patent: US 8,375,064 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: H03M 13/096 Checksums

Abstract

An apparatus, system, and method are disclosed for read back verification of stored data. A file CRC module calculates a first file CRC for a data file. A segmentation module segments the data file into a plurality of data blocks that comprise a copy of the data file. A block CRC module calculates a data block CRC for each data block. An aggregated CRC module calculates a second file CRC from the data block CRCs. In addition, the aggregated CRC module verifies copy of the data file if the second file CRC is substantially equivalent to the first file CRC.

Claims

1. An apparatus for read back verification of stored data, the apparatus comprising:

a file CRC module configured to calculate a first file CRC for a data file;

a segmentation module configured to segment the data file into a plurality of data blocks;

a block CRC module configured to calculate a data block CRC for each data block;

an aggregated CRC module configured to calculate a second file CRC from the data block CRCs and verify a copy of the data file in response to the second file CRC being substantially equivalent to the first file CRC.

2. The apparatus of claim 1, wherein the block CRC module is further configured to append each data block CRC to the corresponding data block.

3. The apparatus of claim 2, further comprising a data channel configured to write each data block with appended data block CRC to a storage medium.

4. The apparatus of claim 3, the data channel further configured to read the data block CRCs from the storage medium.

5. The apparatus of claim 1, wherein the aggregated CRC module is further configured to calculate the second file CRC using Galois field math.

6. The apparatus of claim 1, wherein the file CRC module and the block CRC module calculate each file CRC and data block CRC as a linear checksum.

7. A computer program product comprising a computer useable medium having a computer readable program, wherein the computer readable program when executed on a computer causes the computer to:

calculate a first file CRC for a data file;

segment the data file into a plurality of data blocks comprising a copy of the data file;

calculate a data block CRC for each data block;

calculate a second file CRC from the data block CRCs; and

verify the copy of the data file in response to the second file CRC being substantially equivalent to the first file CRC.

8. The computer program product of claim 7, wherein the computer readable code is further configured to append each data block CRC to the corresponding data block.

9. The computer program product of claim 8, wherein the computer readable code is further configured to write each data block with appended data block CRC to a storage device.

10. The computer program product of claim 9, wherein the computer readable code is further configured to read the data block CRCs from the storage device.

11. The computer program product of claim 7, wherein the computer readable code is further configured to cause the computer to calculate the second file CRC using Galois field math.

12. The computer program product of claim 7, wherein the computer readable code is further configured to cause the computer to calculate each file CRC and data block CRC as a linear checksum.

13. The computer program product of claim 7, wherein a data block size is variable.

14. The computer program product of claim 7, wherein a data block size is fixed.

15. The computer program product of claim 14, wherein the data block size is in the range of one byte to sixteen megabytes.

16. A system for read back verification of stored data, the system comprising:

a storage controller configured to receive a data file and comprising

a file CRC module configured to calculate a first file CRC for the data file;

a storage module configured to store the first file CRC;

a segmentation module configured to segment the data file into a plurality of data blocks;

a storage device comprising

a storage medium configured to store data;

a block CRC module configured to calculate a data block CRC for each data block and append each data block CRC to the corresponding data block;

a data channel configured to write each data block with appended data block CRC to the storage medium as a copy of the data file and read the data block CRCs from the storage medium; and

the storage controller further comprising

an aggregated CRC module configured to calculate a second file CRC from the data block CRCs and verify the copy of the data file in response to the second file CRC being substantially equivalent to the stored first file CRC.

17. The system of claim 16, wherein the file CRC module and the block CRC module calculate each file CRC and data block CRC as a linear checksum.

18. The system of claim 17, wherein the aggregated CRC module is further configured to calculate the second file CRC using Galois field math.

19. The system of claim 18, wherein the storage device is configured as a magnetic tape drive.

20. A method for deploying computer infrastructure, comprising integrating computer-readable code into a computing system, wherein the code in combination with the computing system is capable of performing the following:

calculating a first file CRC for a data file;

segmenting the data file into a plurality of data blocks;

calculating a data block CRC for each data block;

appending each data block CRC to the corresponding data block;

writing each data block with appended data block CRC to a storage device as a copy of the data file;

reading the data block CRCs from the storage device;

calculating a second file CRC from the data block CRCs; and

verifying the copy of the data file in response to the second file CRC being substantially equivalent to the first file CRC.