Abstract: A uniform and symmetric, double failure-correcting technique protects against two or fewer disk failures in a disk array of a storage system. A RAID system of the storage system generates two disks worth of “redundant” information for storage in the array, wherein the redundant information (e.g., parity) is illustratively derived from computations along both diagonal parity sets (“diagonals”) and row parity sets (“rows”). Specifically, the RAID system computes row parity along rows of the array and diagonal parity along diagonals of the array. However, the contents of the redundant (parity) information disks interact such that neither disk contains purely (solely) diagonal or row redundancy information; the redundant information is generated using diagonal parity results in row parity computations (and vice versa).

Abstract: The present invention is an apparatus for indicating valid data in a removable memory media. In an embodiment of the invention, an alert may be employed with the removable media, such as NVRAM, to indicate that the battery backup is functional and that the memory content may be valid. One type of alert may be a blinking light source, such as a blinking light emitting diode (LED). In a another aspect of the present invention, contents of an appliance, such as a computer or storage controller, may be arranged so that an alert employed on the removable memory media in accordance with the present invention may be visible to an administrator without opening the chassis of the appliance.

Abstract: A user interface system that simplifies management of a storage system, such as a multi-protocol storage appliance, by a user or system administrator. The user interface system comprise a command line interface (CLI) and/or a graphical user interface (GUI) that obviates the need for the system administrator to explicitly configure and specify disks used when creating virtual disks (vdisks) that may be exported as logical unit numbers (luns). Management of the storage appliance is further simplified through the use of a novel command set used to, inter alia, create a vdisk, destroy a vdisk, increase/decrease the size of a vdisk, and manage an initiator group (igroup).