Detecting low-level data corruption

In a computer system that includes an operating system, one or more application programs, a magnetic hard disk, and one or more drivers situated in a communication path between the one or more application programs and the magnetic hard disk, wherein one of the drivers included in the one or more drivers is a checksum driver that calculates checksum values for data blocks that are transferred along the communication path, a method for detecting data corruption, the method comprising:

• an act of performing a write operation that causes a data block to be transferred to the magnetic hard disk;
• an act of calculating a first checksum value for the data block as the data block is being transferred as a result of performance of the write operation;
• an act of performing a read operation that causes the data block to be transferred from the magnetic hard disk;
• an act of generating a second checksum value for the data block as the data block is being transferred as a result of performance of the read operation;
• and
• an act of comparing the first checksum value and the second checksum value.

In a computer system that includes an operating system, one or more application programs, a magnetic hard disk, and one or more drivers situated in a communication path between the one or more application programs and the hard disk drive, wherein one of the drivers included in the one or more drivers is a checksum driver that calculates checksum values for data blocks that are transferred along the communication path, a method for detecting data corruption, the method comprising:

• an act of performing a first read operation that causes a data block to be transferred from the magnetic hard disk;
• an act of calculating a first checksum value for the data block as the data block is being transferred as a result of performance of the first read operation;
• an act of performing a second read operation that causes the data block to be transferred from the magnetic hard disk;
• an act of generating a second checksum value for the data block as the data block is being transferred as a result of performance of the second read operation;
• and
• an act of comparing the first checksum value and the second checksum value.

A computer program product for use in a computer system that includes an operating system, one or more application programs, a mass storage location, and one or more drivers situated in a communication path between the one or more application programs and the mass storage location, wherein one of the drivers included in one or more drivers is a checksum driver that calculates checksum values for data blocks that are transferred along the communication path, the computer program product for implementing a method for detecting data corruption, the computer program product comprising:

• one or more computer-readable media carrying computer-executable instructions, that when executed at the computer system, cause the computer system to perform the method, including:
• performing an I/O operation that causes a data block to be transferred along the communication path;
• calculating a first checksum value for the data block as the data block is being transferred;
• performing a subsequent I/O operation that causes the data block to be subsequently transferred along the communication path;
• calculating a second checksum value for the data block as the data block is being subsequently transferred;
• and
• comparing the first checksum value and the second checksum value.

A computer program product for use in a computer system that includes an operating system, one or more application programs, a magnetic hard disk, and one or more drivers situated in a communication path between the one or more application programs and the magnetic hard disk, wherein one of the drivers included in the one or more drivers is a checksum driver that calculates checksum values for data blocks that are transferred along the communication path, the computer program product for implementing a method for detecting data corruption, the computer program product comprising:

• one or more computer-readable media carrying computer-executable instructions, that when executed at the computer system, cause the computer system to perform the method, including:
• performing a write operation that causes a data block to be transferred to the magnetic hard disk;
• calculating a first checksum value for the data block as the data block is being transferred as a result of performance of the write operation;
• performing a read operation that causes the data block to be transferred from the magnetic hard disk;
• generating a second checksum value for the data block as the data block is being transferred as a result of performance of the read operation;
• and
• comparing the first checksum value and the second checksum value.

In a computer system that contains an operating system, one or more application programs, a mass storage location, and a plurality of drivers situated in a communication path between the one or more application programs and the mass storage location, wherein at least two of the drivers included in the plurality of drivers are checksum filter drivers that calculates checksum values for data blocks that are transferred along the communication path, a method for detecting data corruption, the method comprising:

• an act of performing an initial I/O operation that causes a data block to be transferred along the communication path;
• an act of calculating, at a first checksum filter driver, a first checksum value for the data block as the data block is being transferred;
• an act of calculating, at a second checksum filter driver, a second checksum value for the data block as the data block is being subsequently transferred;
• and
• an act of comparing the first checksum value and the second checksum value.