Target DASD controlled data migration move
September 12, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesManaging data storage devices connected to a digital computer Method for moving VSAM base clusters while maintaining alternate indices into the cluster Data storage system for providing redundant copies of data on different disk drives Disk control system in which spare disk and master disks are dynamically exchanged Shared, distributed lock manager for loosely coupled processing systems Real time data migration system and method employing sparse files System for asynchronously duplexing remote data by sending DASD data grouped as a unit periodically established by checkpoint based upon the latest time value High speed online copy of partitioned data Method for incrementally archiving primary storage to archive storage by utilizing both a partition archive status array and a partition map System for migrating data by selecting a first or second transfer means based on the status of a data element map initialized to a predetermined state Patent #: 5680640 InventorsApplicationNo. 711623 filed on 09/12/1996US Classes:711/162, Backup711/112Direct access storage device (DASD)ExaminersPrimary: Swann, Tod R.Assistant: Chow, Christopher S. Attorney, Agent or FirmForeign Patent References
International ClassG06F 012/02AbstractNon-disruptive data migration moves are performed form a source DASD to target DASD in a data subsystem. Both source and target DASDs comprise a cache and a nonvolatile store (NVS). Relative to the host, the target DASD generally operates as a source, managing requests for access to source DASD data by issuing I/O requests to the source DASD. First, the target DASD initiates a background data transfer, where data is copied from the source DASD to the target DASD preparing the target DASD to replace the source DASD. The data transfer includes copying data items directly from the source DASD's cache to that of the target DASD's cache, as well as copying data items from the source DASD's NVS to the target DASD's NVS. During background data transfer, the host can still perform data access operations, such as reads and writes, using the target DASD. Namely, for data already copied from the source DASD to the target DASD, the host reads this data from the target DASD. Host requests to read data not yet copied to the source DASD causes staging of the data from the source DASD to the target DASD. For host write requests, the data to be written to the target DASD, if no source data is needed to complete the write. To satisfy host write requests requiring data not yet copied from the source DASD, the data is copied from the source DASD to the target DASD.Other References
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