摘要:
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.
摘要:
Tissue may be cut and extracted from an interior location in a patient's body using a probe or tool which both effects cutting and causes vaporization of a liquid or other fluid to propel the cut tissue through an extraction lumen of the cutting device. The cutting may be achieved using an electrosurgical electrode assembly, including a first electrode on a cutting member and a second electrode within a cutting probe or tool. Thus, over a first cutting portion, radio frequency current may help cut the tissue and over a second or over transition region, the RF current may initiate vaporization of the fluid or other liquid to propel the tissue from the cutting device.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A system which provides a completely 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 array controllers perform a command and data logging function which stores all host write commands and data ‘missed’ by the backup storage array during a situation wherein the links between the sites are down, the remote site is down, or where a site failover to the remote site has occurred. Log units are used to store, in order, all commands and data for every transaction which was ‘missed’ by the backup storage array when one of the above system error conditions has occurred. The system provides rapid and accurate recovery of backup data at the remote site by sending all logged commands and data from the logging site over the link to the backup site in order, while avoiding the overhead of a full copy operation.
摘要:
Methods and apparatus for precisely applying finely spaced grid lines to an existing shaft on site include, in a first embodiment, attachment of a master grid line carrier to the shaft. In preferred embodiments, the carrier is helically wrapped about the shaft or mated at a diagonal seam across the carrier. Photosensitive material is then applied to the shaft at one or more axial locations. The shaft is rotated and passage of the grid lines on the master is sensed. A light source synchronized to the detection of the master grid lines exposes the photosensitive material as the shaft is rotated to create identical sets of finely spaced grid lines at multiple axial locations on the shaft. The invention also includes a synchronous laser Dopper velocimeter (SLDV) which accurately senses the passage of the lines on the shaft. An extremely accurate torsional interferometer can be constructed using the SLDVs.