Data protection for variable length records by utilizing high performance block storage metadata

US9141477B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Stefan Amann · Eppelheim, DE
• Gerhard Banzhaf · Nufringen, DE
• Kenneth Wayne Boyd · Tucson, US
• Kenneth Fairclough Day, III · Tucson, US
• Jeffrey W. Palm · Rochester, US
• Helmut H. Weber · Waldenbuch, DE
• Harry M. Yudenfriend · Poughkeepsie, US

Key dates

• Filing date: Apr 9, 2008
• Grant date: Sep 22, 2015
• Expiry date: Apr 9, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F11/1004
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

An enhanced mechanism for providing data protection for variable length records utilizes high performance block storage metadata. In an embodiment, an emulated record that emulates a variable length record, such as a Count-Key-Data (CKD) record or an Extended-Count-Key-Data (ECKD) record, is generated by a Host Bus Adapter (HBA) of a mainframe system. The emulated record comprises a sequence of extended fixed-length blocks, each of which includes a data block and a footer. A confluence of the footers defines a high performance block storage metadata unit associated with the emulated record and includes a checksum that covers all data blocks and all footers of the entire emulated record. In one embodiment, the checksum is checked during transit of the emulated record between a HBA and a storage subsystem (e.g., by the HBA when the emulated record is received from the storage subsystem, and/or by a switch in the data transfer path), during a hardening step when writing the emulated record to a disk, and/or during a verification step when reading the emulated record from the disk.