| 摘要 |
A device, system and methods of data management are disclosed, which facilitate the implementation of improved mirroring, back-up, volume remapping, extent relocation, prefetching, caching, data reformatting, statistic gathering, and data translation, among others. A new, intelligent I/O stream splitter is disclosed that may intercept and alter an I/O stream received by the splitter from a communications link. For example, in the case of mirroring, the intelligent splitter may intercept write commands and associated data from a mainframe that target a specific storage location on a specific control unit. The splitter may then transmit the intercepted I/O stream to the targeted control unit and storage location over one link and in parallel transmit on another link an altered version of the intercepted I/O stream to another control unit, which is responsible for holding a mirrored version of the data. The altered version could have the same data as that on the one link but have new frame headers injected at appropriate points in the I/O stream. Moreover, the intelligent splitter may improve the functionality of extended functions such as mirroring as well. The alterations to the I/O stream to the mirroring control unit may include changes to the control information of the I/O stream, for example, to address the mirroring control instead of the primary unit. But the alterations may also include changes to the data itself, including formatting, filtering and translating. A host may be connected to potentially several intelligent splitters to implement extended functions cooperatively. Among other things, the host may be used to configure the splitter to perform the mirroring (or other) operation at a physical level of addressing, though the host may receive requests expressed at a logical level. The host may then map the logical name to physical addresses and configure the splitter accordingly. The host may also instruct the splitter to create and send streams independently of any I/O streams passing through the splitter. This created I/O stream may correspond to an entire CCW in ESCON contexts.
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