Abstract: Managing a redundant array of independent disks (RAID) storage array involves assigning first and second stripes to span respective first and second sets of disks. A subset of drives in the first set fails such that the first stripe is in a first state wherein a failure of another drive in the first set will lead to data loss in the first stripe. It is determined that the second stripe is in a fault-tolerant state such that the second stripe can have failures of two drives in the second set before the second stripe is in the first state, Part of an operational disk of the second set used by the second stripe is allocated to the first stripe to replace at least part of the subset of failed drives.

Abstract: Managing a redundant array of independent disks (RAID) storage array involves assigning first and second stripes to span respective first and second sets of disks. A subset of drives in the first set fails such that the first stripe is in a first state wherein a failure of another drive in the first set will lead to data loss in the first stripe. It is determined that the second stripe is in a fault-tolerant state such that the second stripe can have failures of two drives in the second set before the second stripe is in the first state, Part of an operational disk of the second set used by the second stripe is allocated to the first stripe to replace at least part of the subset of failed drives.

Abstract: The technology disclosed herein includes a method for dividing a body of user data into a plurality of data blocks, and writing the plurality of data blocks into chunk zones in parallel streams, the chunk zones located in a first ordered pool of storage devices. In some implementations, the method includes adding additional storage devices to the first ordered pool making a second ordered pool, including the first ordered pool, and writing the plurality of data blocks across the second ordered pool of storage devices, such that each of the storage devices including spare capacity. The method includes determining if a storage device fails, and seeking data for the data blocks on the failed storage device from of the other storage devices.

Abstract: A method for maintaining reliable communication between a command initiator and a target device is provided. After the command initiator detects an error corresponding to the target device and a path between the command initiator and the target device, the command initiator performs a downshift evaluation. The initiator maintains a transmission speed if the downshift evaluation determines that forgoing a transmission speed downshift is required, and reduces the transmission speed if the downshift evaluation determines that transmission speed downshift is required. The command initiator then logs the downshift evaluation result and reports any transmission speed change to a user.

Abstract: A method for maintaining reliable communication between a command initiator and a target device is provided. After the command initiator detects an error corresponding to the target device and a path between the command initiator and the target device, the command initiator performs a downshift evaluation. The initiator maintains a transmission speed if the downshift evaluation determines that forgoing a transmission speed downshift is required, and reduces the transmission speed if the downshift evaluation determines that transmission speed downshift is required. The command initiator then logs the downshift evaluation result and reports any transmission speed change to a user.