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.