Abstract: A system and method for managing distributed coherent datasets using a hierarchical change log is provided. In some embodiments, a distributed storage system is provided that includes a primary storage device containing a primary dataset and a mirror storage device containing a mirror dataset. The mirror dataset includes a coherent copy of the primary dataset. The distributed storage system further includes a hierarchical change log tracking a coherence state for the mirror dataset. The hierarchical change log includes a first sub-log and a second sub-log, and a block range of the first sub-log overlaps a block range of the second sub-log. The hierarchical change log may define a priority relationship between the first sub-log and the second sub-log governing the overlap. The first sub-log and the second sub-log may be independently configured and may be different in one of a representation and a block size.

Abstract: A system and method for managing distributed coherent datasets using a hierarchical change log is provided. In some embodiments, a distributed storage system is provided that includes a primary storage device containing a primary dataset and a mirror storage device containing a mirror dataset. The mirror dataset includes a coherent copy of the primary dataset. The distributed storage system further includes a hierarchical change log tracking a coherence state for the mirror dataset. The hierarchical change log includes a first sub-log and a second sub-log, and a block range of the first sub-log overlaps a block range of the second sub-log. The hierarchical change log may define a priority relationship between the first sub-log and the second sub-log governing the overlap. The first sub-log and the second sub-log may be independently configured and may be different in one of a representation and a block size.

Abstract: A system and method for managing distributed coherent datasets using a hierarchical change log is provided. In some embodiments, a distributed storage system is provided that includes a primary storage device containing a primary dataset and a mirror storage device containing a mirror dataset. The mirror dataset includes a coherent copy of the primary dataset. The distributed storage system further includes a hierarchical change log tracking a coherence state for the mirror dataset. The hierarchical change log includes a first sub-log and a second sub-log, and a block range of the first sub-log overlaps a block range of the second sub-log. The hierarchical change log may define a priority relationship between the first sub-log and the second sub-log governing the overlap. The first sub-log and the second sub-log may be independently configured and may be different in one of a representation and a block size.

Abstract: A system and method for managing distributed coherent datasets using a hierarchical change log is provided. In some embodiments, a distributed storage system is provided that includes a primary storage device containing a primary dataset and a mirror storage device containing a mirror dataset. The mirror dataset includes a coherent copy of the primary dataset. The distributed storage system further includes a hierarchical change log tracking a coherence state for the mirror dataset. The hierarchical change log includes a first sub-log and a second sub-log, and a block range of the first sub-log overlaps a block range of the second sub-log. The hierarchical change log may define a priority relationship between the first sub-log and the second sub-log governing the overlap. The first sub-log and the second sub-log may be independently configured and may be different in one of a representation and a block size.

Abstract: A method and apparatus for transferring data from a first storage system to a second storage system in which the first storage system includes a first plurality of storage devices and the second storage system includes a second plurality of storage devices. Data is transferred using a pair of devices selected for transferring data for all of the storage devices. Data to be transferred from source storage devices within the first plurality of storage devices is placed or queued on a selected primary storage device within the first plurality of storage devices. The data is sent to a selected secondary storage device within the plurality of storage devices. The data is relocated from the selected secondary storage device to target storage devices within the second plurality of storage devices.