Abstract: This disclosure relates to parity declustered storage device arrays having partition groups. In an exemplary embodiment, the storage system includes a storage device array, such as disk array. Each storage device is divided into partitions. Each partition includes stripe units, such as hundreds or thousands of stripe units in exemplary embodiments. The storage system also includes a physical array controller coupled to the storage device array. In an exemplary embodiment, the array controller includes a partition group lookup table and stores and retrieves data and parity in the storage devices based on the partition group lookup table. In this exemplary embodiment, the array controller also includes a stripe lookup table and/or a log. In an exemplary embodiment, the partition group lookup table and the stripe lookup table take up less memory (e.g., by an order of magnitude) than a single-level stripe map conveying the same information.

Abstract: This disclosure relates to parity declustered storage device arrays having partition groups. In an exemplary embodiment, the storage system includes a storage device array, such as disk array. Each storage device is divided into partitions. Each partition includes stripe units, such as hundreds or thousands of stripe units in exemplary embodiments. The storage system also includes a physical array controller coupled to the storage device array. In an exemplary embodiment, the array controller includes a partition group lookup table and stores and retrieves data and parity in the storage devices based on the partition group lookup table. In this exemplary embodiment, the array controller also includes a stripe lookup table and/or a log. In an exemplary embodiment, the partition group lookup table and the stripe lookup table take up less memory (e.g., by an order of magnitude) than a single-level stripe map conveying the same information.

Abstract: A method and system for cache-based dropped write protection in data storage systems are provided. An implementation involves detecting undetected write errors in a storage system, by writing data to a storage medium from a data cache; maintaining a copy of the data in the data cache until said data on the storage medium is validated or said data needs to be evicted from the data cache; and prior to eviction of said data from the data cache, maintaining metadata for said data in a metadata cache until the data written to the storage medium has been validated against the metadata.

Abstract: A system (and method) for determining reconstruction formulas for partial strip reconstruction in a storage system in which a plurality of lost strips have been detected, includes using a combination of a direct reconstruction method and a sequential reconstruction method.

Abstract: A method and device for detecting and handling non-responsive devices in a computer system where the device non-responsiveness may be due to a powered-down status rather than a device failure, and more particularly to such computer systems when the devices are RAID disk drives. By scanning all devices connected in a configuration and maintaining a count of devices that time out without responding, a determination can be made as to whether the devices are powered off or are experiencing some other problem that requires attention of a system support technician.

Abstract: A method and device for detecting and handling non-responsive devices in a computer system where the device non-responsiveness may be due to a powered-down status rather than a device failure, and more particularly to such computer systems when the devices are RAID disk drives. By scanning all devices connected in a configuration and maintaining a count of devices that time out without responding, a determination can be made as to whether the devices are powered off or are experiencing some other problem that requires attention of a system support technician.

Abstract: A method and device for detecting and handling non-responsive devices in a computer system where the device non-responsiveness may be due to a powered-down status rather than a device failure, and more particularly to such computer systems when the devices are RAID disk drives. By scanning all devices connected in a configuration and maintaining a count of devices that time out without responding, a determination can be made as to whether the devices are powered off or are experiencing some other problem that requires attention of a system support technician.