Method for the reliability of host data stored on fibre channel attached storage subsystems
View Patent ↗A method for improving the reliability of host data stored on Fiber Channel attached storage subsystems by performing end-to-end data integrity checks. When a read or write operation is initiated, an initial checksum for data in the read/write operation is generated and associated with the data, wherein the association exists through a plurality of layers of software and attached storage subsystems. The initial checksum is passed with the data in the read/write path. When a layer of software in the read/write path receives the initial checksum and data, the layer performs an integrity check of the data, which includes generating another checksum and comparing it to the initial checksum. If the checksums do not match, the read/write operation fails and the error is logged. If the checksums match, the integrity check is repeated through each layer in the read/write path to enable detecting data corruption at the point of source.
1. A method in a data processing system for providing end-to-end data integrity checks, the method comprising:
performing a read/write operation, wherein the read/write operation comprises generating an initial checksum for data in the read/write operation and associating the initial checksum with the data, wherein the association exists through a plurality of layers of a software and attached storage subsystems in the data processing system;
sending the initial checksum with the data through the plurality of layers of the software and attached storage subsystems in a read/write path;
responsive to receiving the initial checksum and data at each layer in the plurality of layers of the software and attached storage subsystems in the read/write path, performing an integrity check in the plurality of layers of the software and attached storage subsystems of the data, wherein the integrity check comprises generating a comparison checksum and determining whether the comparison checksum matches the initial checksum at each layer in the plurality of layers of the software and attached storage subsystems;
if the initial checksum and the comparison checksum do not match, failing the read/write operation;
responsive to failing the read/write operation, performing the integrity check in additional levels of the software to detect a layer of the software at which the integrity check failed; and
generating return code by the layer of the software at which the integrity check failed, wherein the return code includes data related to a failure of the integrity check.
2. The method of claim 1 , further comprising:
if the initial checksum and the comparison checksum match, repeating the integrity check in each layer of the plurality of the layers of software and attached storage subsystems in the read/write path.
3. The method of claim 1 , wherein determining whether the comparison checksum matches the initial checksum at each layer in the plurality of layers of the software and attached storage subsystems allows for detecting data corruption at a point of source.
4. The method of claim 1 , wherein failing the read/write operation includes logging an error and sending a read/write failure notification to a user.
5. The method of claim 1 , wherein the initial checksum is sent in a header of a communication medium.
6. The method of claim 5 , wherein the communication medium is one of Fibre Channel and iSCSI.
7. The method of claim 1 , wherein the integrity check is performed without imposing a restriction on structure, form, and content of the data.
8. The method of claim 1 , wherein performing the integrity check in the plurality of layers of the software and attached storage subsystems in the read/write path prevents corrupted data from being stored on disk.