Abstract: This disclosure describes techniques that include implementing network-efficient data durability or data reliability coding on a network. In one example, this disclosure describes a method that includes generating a plurality of data fragments from data to enable reconstruction of the data from a subset of the plurality of data fragments; storing, across a plurality of nodes in a network, the plurality of data fragments, wherein storing the plurality of data fragments includes storing the first fragment at a first node and the second fragment at a second node; and generating, by the first node, a plurality of secondary fragments derived from the first fragment to enable reconstruction of the first fragment from a subset of the plurality of secondary fragments; and storing the plurality of secondary fragments from the first fragment across a plurality of storage devices included within the first node.

Abstract: This disclosure describes techniques that include implementing network-efficient data durability or data reliability coding on a network. In one example, this disclosure describes a method that includes generating a plurality of data fragments from a set of data to enable reconstruction of the set of data from a subset of the plurality of data fragments; storing, across a plurality of nodes in a network, the plurality of data fragments, wherein storing the plurality of data fragments includes storing the first fragment at a first node and the second fragment at a second node; and generating, by the first node, a plurality of secondary fragments derived from the first fragment to enable reconstruction of the first fragment from a subset of the plurality of secondary fragments; and storing the plurality of secondary fragments from the first fragment across a plurality of storage devices included within the first node.

Abstract: This disclosure describes techniques that include implementing network-efficient data durability or data reliability coding on a network. In one example, this disclosure describes a method that includes generating a plurality of data fragments from a set of data to enable reconstruction of the set of data from a subset of the plurality of data fragments; storing, across a plurality of nodes in a network, the plurality of data fragments, wherein storing the plurality of data fragments includes storing the first fragment at a first node and the second fragment at a second node; and generating, by the first node, a plurality of secondary fragments derived from the first fragment to enable reconstruction of the first fragment from a subset of the plurality of secondary fragments; and storing the plurality of secondary fragments from the first fragment across a plurality of storage devices included within the first node.

Abstract: Protection from uncorrectable media errors are provided for a RAID-configured storage system by a technique in which c redundancy information sectors are associated with n data information sectors. The n data sectors and c redundancy information sectors are then written as a single segment on a single storage unit. The RAID-configured storage system can be configured, for example, as a RAID 6 storage system, a RAID 5 storage system, a RAID 51 storage system, a RAID 3+3 storage system or a RAID N+3 storage system. The redundancy information can be based on a Reed-Solomon code, an XOR-based code, or one-dimensional parity.

Abstract: Provided are a method, system, and program for managing a network providing Input/Output (I/O) paths between a plurality of host systems and storage volumes in storage systems. An application service connection definition is provided for each connection from a host to a storage volume. At least one service level guarantee definition is provided indicating performance criteria to satisfy service requirements included in at least one service level agreement with at least one customer for network resources. Each service level guarantee definition is associated with at least one application service connection definition. Monitoring is performed as to whether Input/Output (I/O) requests transmitted through the multiple I/O paths satisfy performance criteria indicated in the service level guarantee definition associated with the I/O paths.

Abstract: A method for rebuilding contents of a malfunctioned direct access storage device within a log-structured array is disclosed. In accordance with the method and system of the present invention, each direct access storage device within a log-structured array is divided into multiple segment-columns, and each corresponding segment-column from each direct access storage device within the log-structured array forms a segment. A segment is first located within the direct access storage devices. A determination is made as to whether or not the segment is empty. In response to a determination that the segment is empty, a pointer is moved within a segment-column mapping table from pointing to a segment-column in the malfunctioned direct access storage device to point to a segment-column in a spare direct access storage device of the segment.

Abstract: A method for rebuilding contents of a malfunctioned direct access storage device within a log-structured array is disclosed. In accordance with the method and system of the present invention, each direct access storage device within a log-structured array is divided into multiple segment-columns, and each corresponding segment-column from each direct access storage device within the log-structured array forms a segment. A segment is first located within the direct access storage devices. A determination is made as to whether or not the segment is empty. In response to a determination that the segment is empty, a pointer is moved within a segment-column mapping table from pointing to a segment-column in the malfunctioned direct access storage device to point to a segment-column in a spare direct access storage device of the segment.

Abstract: A data storage system and method for operating a disk controller, and also a disk controller operated in accordance with the method are disclosed. The method includes the steps of allocating a first amount of disk space for a compressed data unit as a first predetermined percentage of an uncompressed size of the data unit; and then increasing the allocation by a second predetermined percentage that is less than the first predetermined percentage to obtain a total amount of allocated disk space. The first predetermined percentage is a function of an expected compression ratio for the data unit, and the second predetermined percentage is a function of an expected change in the size of the compressed data unit as a result of an update operation performed on the data unit.