Abstract: The device is a portable umbrella attachment used to mount on the frame of any glass embedded automobile door. It is equipped to support the weight and torque of an umbrella during adverse weather conditions. The device extends the functionality of an umbrella to allow it to serve as a shield and limit weather elements like rain, hail, and snow from entering the user's open automobile door. It also protects the driver or passengers from bad weather elements while they enter, exit or stand by the automobile. The affixing mechanism is designed to apply enough forceful pressure such as a squeezing/gripping motion to secure the umbrella's handle into the device or securely attach the device to a glass embedded automobile door frame. Thus, the user can singlehandedly maneuver this motion. The device has an adjustable shaft; thus, the user can change the direction of the umbrella depending on the situation.

Abstract: Method and apparatus for managing the storage of data in a cache memory by placing pending read requests for sequential data in a dedicated read ahead stream control (RASC) data structure, and further configured for dynamically switching both ways, in response to data stored in the RASC, between speculative non-requested read ahead data streaming to read behind stream locking on the read requests in the RASC.

Abstract: Method and apparatus for allocating system resources for use by software processes in a computer-based system, such as a wide area network (WAN) comprising a data storage array. A first memory space provides a first bit indicator to indicate whether at least one system resource is available for use. A second memory space provides a second bit indicator to indicate whether a pending software process awaits availability of the system resource. The resource is allocated for use by the process in relation to a combinatorial operation upon the first and second bit indicators, preferably comprising a logical AND operation. The first and second memory spaces are preferably characterized as multi-bit registers. A free resource stack identifies available resources, and a process queue identifies pending processes waiting for released processes. The statuses of the respective stack and queue are reflected in the bits in the multi-bit registers.

Abstract: Method and apparatus for wave flushing cached writeback data to a storage array. A cache manager operates to initiate a wave flushing operation whereby sets of writeback data in a cache memory are sequentially written to each of a plurality of logical groups radially concentric with respect to the storage medium. During the wave flushing operation, a write transducer is radially advanced across the medium in a single radial direction across boundaries between immediately adjacent groups. The write operations thus form a traveling wave across the medium, analogous to a wave in a sports stadium formed by spectators standing up and sitting down in turn. Each logical group preferably corresponds to a selected transducer seek range, such as an associated RAID stripe. Seeks are preferably bi-directional within each group, and uni-directional between adjacent groups. A dwell time (service time interval) for each group can be constant, or adaptively adjusted.

Abstract: Method and apparatus for caching and retaining non-requested speculative data from a storage array in an effort to accommodate future requests for such data. A cache manager stores requested readback data from the storage array to a cache memory, and selectively transfers speculative non-requested readback data to the cache memory in relation to a time parameter and a locality parameter associated with a data structure of which the requested readback data forms a part. The locality parameter preferably comprises a stream count as an incremented count of consecutive read requests for a contiguous data range of the storage array, and the time parameter preferably indicates a time range over which said read requests have been issued. The speculative readback data are transferred when both said parameters fall within a selected threshold range. The data structure preferably comprises a RAID stripe on a selected storage device of the array.

Abstract: Method and apparatus for caching readback data in a cache memory. Upon a transfer of cached readback data to a host device, a cache manager operates to force a retention of the readback data in the cache memory in relation to a time parameter and a locality parameter associated with said data. In this way, the readback data are either retained in hopes of satisfying a subsequent cache hit, or not retained to accommodate subsequently cached data. Preferably, the cache manager compares the time parameter to a time threshold and the locality parameter to a locality threshold, and forces said retention of the readback data if both said thresholds are met. The readback data is preferably associated with a data structure such as a RAID stripe, the time parameter preferably indicates elapsed time since last access to the structure and the locality parameter preferably indicates accesses to the structure.

Abstract: Method and apparatus for logging and analyzing event flows associated with execution of a service request in a software system, such as a computer-based system comprising a multi-disc data storage array. Execution of the service request results in a plurality of events carried out by multiple layers of the software system. A global event log accumulates a corresponding plurality of entries which associates each of the events carried out by the multiple layers. An event trace facility preferably accesses the global event log to provide a sequence of the entries corresponding to the service request, such as in a tree structure or time sequence order displayed by a graphical user interface. A log manager preferably controls operation of the global event log. Entries in the global event log are preferably entered sequentially for each ongoing process, and each entry preferably includes an identifier that identifies the associated service request.

Abstract: A data storage system is provided with a pair of controllers and circuitry configured for failing back from a single active write back mode to a dual active write back mode by copying cached data directly from a cache of a survivor controller of the pair of controllers to a cache of the other controller. A method is provided for failing over from a dual active mode of first and second controllers to a single active mode of the first controller by relying on previously mirrored cache data by the second controller; reinitializing the second controller; and failing back to the dual active mode by copying cached data directly from the first controller to the second controller.

Abstract: Method and apparatus for caching readback data in a cache memory. Upon a transfer of cached readback data to a host device, a cache manager operates to force a retention of the readback data in the cache memory in relation to a time parameter and a locality parameter associated with said data. In this way, the readback data are either retained in hopes of satisfying a subsequent cache hit, or not retained to accommodate subsequently cached data. Preferably, the cache manager compares the time parameter to a time threshold and the locality parameter to a locality threshold, and forces said retention of the readback data if both said thresholds are met. The readback data is preferably associated with a data structure such as a RAID stripe, the time parameter preferably indicates elapsed time since last access to the structure and the locality parameter preferably indicates accesses to the structure.

Abstract: Method and apparatus for wave flushing cached writeback data to a storage array. A cache manager operates to initiate a wave flushing operation whereby sets of writeback data in a cache memory are sequentially written to each of a plurality of logical groups radially concentric with respect to the storage medium. During the wave flushing operation, a write transducer is radially advanced across the medium in a single radial direction across boundaries between immediately adjacent groups. The write operations thus form a traveling wave across the medium, analogous to a wave in a sports stadium formed by spectators standing up and sitting down in turn. Each logical group preferably corresponds to a selected transducer seek range, such as an associated RAID stripe. Seeks are preferably bi-directional within each group, and uni-directional between adjacent groups. A dwell time (service time interval) for each group can be constant, or adaptively adjusted.

Abstract: Method and apparatus for adaptive arrangement of data on storage media, such as in a multi-device storage array across which data are stored. A virtual hot space is formed to store frequently accessed data. The virtual hot space comprises at least one hot data zone which extends across storage media of a plurality of arrayed storage devices over a selected seek range less than an overall radial width of the media. The frequently accessed data are stored to the hot data zone(s) in response to a host level request, such as from a host level operating system (OS) or by a user which identifies the data as frequently accessed data. Alternatively or additionally, access statistics are accumulated and frequently accessed data are migrated to the hot data zone(s) in relation thereto. Lower accessed data sets are further preferably migrated from the hot data zone(s) to another location of the media.

Abstract: Method and apparatus for caching and retaining non-requested speculative data from a storage array in an effort to accommodate future requests for such data. A cache manager stores requested readback data from the storage array to a cache memory, and selectively transfers speculative non-requested readback data to the cache memory in relation to a time parameter and a locality parameter associated with a data structure of which the requested readback data forms a part. The locality parameter preferably comprises a stream count as an incremented count of consecutive read requests for a contiguous data range of the storage array, and the time parameter preferably indicates a time range over which said read requests have been issued. The speculative readback data are transferred when both said parameters fall within a selected threshold range. The data structure preferably comprises a RAID stripe on a selected storage device of the array.

Abstract: Method and apparatus for managing the storage of data in a cache memory by placing pending read requests for sequential data in a dedicated read ahead stream control (RASC) data structure, and further configured for dynamically switching both ways, in response to data stored in the RASC, between speculative non-requested read ahead data streaming to read behind stream locking on the read requests in the RASC.

Abstract: A data storage system is provided with a pair of controllers and circuitry configured for failing back from a single active write back mode to a dual active write back mode by copying cached data directly from a cache of a survivor controller of the pair of controllers to a cache of the other controller. A method is provided for failing over from a dual active mode of first and second controllers to a single active mode of the first controller by relying on previously mirrored cache data by the second controller; reinitializing the second controller; and failing back to the dual active mode by copying cached data directly from the first controller to the second controller.

Abstract: Method and apparatus for flushing cached writeback data to a storage array. Sets of writeback data are accumulated in a cache memory in an array with a view toward maintaining a substantially uniform distribution of the data across different locations of the storage array. The arrayed sets of data are thereafter transferred from the cache memory to the storage array substantially at a rate at which additional sets of writeback data are provided to the cache memory by a host. Each set of writeback data preferably comprises a plurality of contiguous data blocks, and are preferably written (flushed) to the storage in conjunction with the operation of a separate access command within a selected proximity range of the data with respect to the storage array. A stripe data descriptor (SDD) is preferably maintained for each set of writeback data in the array.

Abstract: A disaster-tolerant data backup and remote copy system which is implemented as a controller-based replication of one or more LUNs (logical units) between two remotely separated pairs of array controllers connected by redundant links. In the situation wherein an array controller fails during an asynchronous copy operation, the partner array controller uses a ‘micro log’ stored in mirrored cache memory to recover transactions, in order, which were ‘missed’ by the backup storage array when the array controller failure occurred.

Abstract: A data replication system having a redundant configuration including dual Fiber Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The system employs the grouping of logical units into ‘association sets’, for logging and failover purposes. The concept of association sets allows the system provides for proper ordering of I/O operations during logging across multiple volumes. In addition, association sets are employed by system to provide failure consistency by causing the group of logical units/volumes to all fail at the same time, ensuring a point in time consistency on the remote site.

Abstract: A disaster-tolerant data backup and remote copy system which is implemented as a controller-based replication of one or more LUNs (logical units) between two remotely separated pairs of array controllers connected by redundant links. The system provides a method for allowing a large number of commands to be ‘outstanding’ in transit between local and remote sites while ensuring the proper ordering of commands on remote media during asynchronous or synchronous data replication. In addition, the system provides a mechanism for automatic ‘tuning’ of links based on the distance between the array controllers.

Abstract: A data replication system having a redundant configuration including dual Fibre Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The system employs the grouping of logical units into ‘association sets’, for logging and failover purposes. The concept of association sets allows the system provides for proper ordering of I/O operations during logging across multiple volumes. In addition, association sets are employed by system to provide failure consistency by causing the group of logical units/volumes to all fail at the same time, ensuring a point in time consistency on the remote site.

Abstract: A disaster-tolerant data backup and remote copy system which is implemented as a controller-based replication of one or more LUNs (logical units) between two remotely separated pairs of array controllers connected by redundant links. The system provides a method for allowing a large number of commands to be ‘outstanding’ in transit between local and remote sites while ensuring the proper ordering of commands on remote media during asynchronous or synchronous data replication. In addition, the system provides a mechanism for automatic ‘tuning’ of links based on the distance between the array controllers.