Abstract: The invention provides a method and system for monitoring status in a relatively continuous consistent and intelligent manner. A status monitor receives monitoring data, and adaptively and dynamically associates those known combinations with assessments of the monitored devices, systems, or networks. From an initial set of selected knowledge (or even no knowledge at all), the status monitor develops a database of information regarding anomalous conditions, and measurements of likely causes and faults and learns which of those anomalous conditions require response. Appropriate responses can include informing a system operator, taking remedial action, and altering or terminating the monitored device, systems or network.

Abstract: The invention provides a file server system and a method for operating that system, which is easily scalable in number and type of individual components. A plurality of file servers are coupled using inter-node connectivity, such as an inter-node network, so that any one node can be accessed from any other node. Each file server includes a pair of file server nodes, each of which has a memory and each of which conducts file server operations by simultaneously writing to its own memory and to that of its twin, the pair being used to simultaneously control a set of storage elements such as disk drives. File server requests directed to particular mass storage elements are routed among file servers using an inter-node switch and processed by the file servers controlling those particular storage elements. The mass storage elements are disposed and controlled to form a redundant array, such as a RAID storage system.

Abstract: A method and apparatus for a reliable data storage system using block level checksums appended to data blocks. Files are stored on hard disks in storage blocks, including data blocks and block-appended checksums. The block-appended checksum includes a checksum of the data block, a VBN, a DBN, and an embedded checksum for checking the integrity of the block-appended checksum itself. A file system includes file blocks with associated block-appended checksum to the data blocks. The file blocks with block-appended checksums are written to storage blocks. In a preferred embodiment a collection of disk drives are formatted with 520 bytes of data per sector. For each 4,096-byte file block, a corresponding 64-byte block-appended checksum is appended to the file block with the first 7 sectors including most of the file block data while the 8th sector includes the remaining file block data and the 64-byte block-appended checksum.

Abstract: A system that adapts wireless link parameters for a wireless communication link. A measure is determined of errors occurring in communication over a wireless link. In a case that the measure of errors corresponds to more errors than a first predetermined threshold, communication changes from a first set of wireless link parameters to a second set of wireless link parameters. The second set of wireless link parameters corresponds to higher error tolerance than the first set of wireless link parameters. In a case that the measure of errors corresponds to fewer errors than a second predetermined threshold, communication changes from the first set of wireless link parameters to a third set of wireless link parameters. The third set of wireless link parameters corresponds to lower error tolerance than the first set of wireless link parameters. Preferably, the measure of errors is determined by monitoring a number of NACK messages and a number of ACK messages that occur.

Abstract: A method and system for auto-detection of communication mismatch, such as in a networking environment. A device using a communication protocol uses a technique for protocol augmentation to determine sufficient information about whether there is a protocol parameter mismatch, and to determine how to adjust its protocol parameters so that the parameter mismatch is obviated. In a preferred embodiment, the protocol includes an Ethernet protocol, and the mismatch includes information about whether devices at ends of a communication link are using half-duplex or full-duplex settings. A first device using the Ethernet generates messages that force a set of second devices using the same Ethernet to generate responsive messages to send to the first device; the first device determines, by examining features of the responsive messages from the second devices, what protocol settings the second devices are using.

Abstract: A heteroscopic turbine with a Knudsen number of less than ten. In one embodiment, the heteroscopic turbine generates a flow from a gas. The turbine includes at least a moving surface and a plurality of turbine blades on or in said surface. Each of the blades has a height comparable to a mean free path distance that characterizes molecules in the gas, and the blades are spaced apart by a distance comparable to the mean free path distance. In operation, the surface moves such that the turbine blades pass through the gas at a speed comparable to the mean thermal velocity. In different embodiments, the turbine can perform filtering of molecules in the gas based on direction and/or speed (velocity). Also, techniques by which such a turbine operates.

Abstract: A method and system allowing a mobile phone user to “opt in” to requests with multiple response options, to respond indicating that user wishes not to be tracked, or to respond indicating some information about state, possibly in addition to PVT information. The user has options besides allowing ping responses or turning off GPS tracking. When a ping is received, user chooses whether or not to opt in to the ping. The user may refuse to respond, to respond normally with or without PVT or other information, or to respond saying only that the mobile phone is turned on. GPS tracking continues to operate, so that upon return to normal responses, no cold start of GPS tracking is involved. More intelligent, such as for example rules-based, responses can be made to ping messages, in which GPS tracking interacts with a user interface to determine how to respond flexibly to pings.

Abstract: An improved method and apparatus for quickly and efficiently updating the original source volume and original target volumes after the original source volume has become temporarily unavailable. The original target volume is characterized as a source volume while the original source volume is temporarily unavailable. Transfer lists of different data blocks are generated. Data blocks not originally found on a source are copied to the target. Data blocks included on a target that were not found on the source are removed. By focusing upon specific data blocks, this technique avoids the use of filer overhead and other computational resources that would be expended if the entire volume were recopied.

Abstract: The invention provides a storage system that is highly available even in the face of component failures in the storage system, and a method for operating that storage system. A first and a second file server each includes a file server request log for storing incoming file server requests. Both the first and second file servers have access to a common set of mass storage elements. Each incoming file server request is copied to both the first and second file servers; the first file server processes the file server request while the second file server maintains a copy in its file server request log. Each file server operates using a file system that maintains consistent state after each file server request. On failover, the second file server can perform those file server requests in its file server request log since the most recent consistent state. There is no single point of failure that prevents access to any individual mass storage element.

Abstract: Apparatus using mechanically-actuated evanascent wave coupling. At least a portion of an optical waveguide is integrated onto a substrate, and an optically active element is physically moved relatively to each other, with the result that propagation parameters for the waveguide are substantially altered. The optically active element may be a resonator or another waveguide. Altered propagation parameters can be used to cause an optical wave to be transformed in response to an electromagnetic signal. Physical parts of the apparatus can vary widely in both size and tolerance. The optically active element is mechanically actuated relative to a position of the optical waveguide.

Abstract: The invention provides a method and system for persistent and reliable delivery of event messages. Those parts of the system responsible for delivering event messages are able to persistently maintain those event messages until the intended recipient of the event message confirms delivery of those event messages. Those parts of the system responsible for recovering from system crashes and other system errors are able to persistently maintain those event messages until delivery, even after recovery from system crashes or other system errors. The system includes a set of event message producers, and maintains an event-indication queue of those event messages provided by the event producers using a set of pre-allocated resources. An event-distribution engine distributes event messages to intended recipients and, after having received confirmation that the event messages were received, removes them from the event-indication queue.

Abstract: A method of generating IP identification numbers for IP datagrams. A plurality of IP identification number generators are maintained. A plurality of receiving stations are associated with the plurality of IP identification number generators such that each receiving station has an IP identification number generator associated therewith. An IP identification number is generated for a datagram sent to a receiving station based on an output of the associated IP identification number generator. Also, a method of reducing a likelihood of misassembly of received data fragments from fragmented IP datagrams. The data fragments have an IP identification number. All received data fragments of the datagram are discarded upon detection of receipt of an overlapping data fragment having the IP identification number. Timeouts for reassembling datagrams are reduced. First, timeouts for reassembling the datagrams are reduced to less than a standard timeout.

Abstract: The present invention provides a method for keeping a file system in a consistent state and for creating read-only copies of a file system. Changes to the file system are tightly controlled. The file system progresses from one self-consistent state to another self-consistent state. The set of self-consistent blocks on disk that is rooted by the root inode is referred to as a consistency point. To implement consistency points, new data is written to unallocated blocks on disk. A new consistency point occurs when the fsinfo block is updated by writing a new root inode for the inode file into it. Thus, as long as the root inode is not updated, the state of the file system represented on disk does not change. The present invention also creates snapshots that are read-only copies of the file system. A snapshot uses no disk space when it is initially created. It is designed so that many different snapshots can be created for the same file system.

Abstract: Propagation of data by mirroring the data from a first filer to a second filer, and then mirroring the data from the second filer to a third filer. More generally, propagating data by mirroring the data along a chain or cascade of mirrors. Snapshots are used in mirroring the data. Preferably, the data is organized in one or more volumes on the filer, and one or more of the volumes are mirrored. Deletion is prevented of a snapshot associated with a volume from a filer until the filer is informed that no other filer needs that snapshot to mirror the volume from the filer. Preferably, each filer uses softlocks to track what snapshots correspond to volumes mirrored down the chain or cascade of filers.

Abstract: The disclosure relates to apparatus and methods that provide a system interconnect for transporting cells between nodes on a dual counter-rotating ring network, including a link selection register for selecting the shortest path to a destination node, use of a fault tolerant frequency reference to synchronize node clocks, interconnect initialization, multi-ring topologies along with an addressing schema and ring-to-ring couplers. The disclosure also discusses flow control of cells leaving nodes, coupling cells from one ring to another, and use of such an interconnect as a bus replacement.

Abstract: A method and system for computer assisted automatic error detection and diagnosis of file servers. Software modules periodically and continuously review monitoring statistics gathered by the file server regarding its operation. The monitoring statistics are processed by a pattern matching system and a rule-based inference system. Software modules augment known network protocols, by manipulating parameters of lower-level protocols using different higher-level protocols. Using the higher-level protocols, software modules determine if the selected parameters for the lower-level protocols are correct. Software modules track hardware and software configuration changes to the file server, and relate changes in known monitoring statistics to timing of those hardware and software configuration changes.

Abstract: A method and system for providing the functionality of dynamically-allocated threads in a multithreaded system, in which the operating system provides only statically-allocated threads. With this functionality, a relatively large number of threads can be maintained without a relatively large amount of overhead (either in memory or processor time), and it remains possible to produce program code without undue complexity. A plurality of dynamically-allocated threads are simulated using a single statically-allocated thread, but with state information regarding each dynamically-allocated thread maintained within the single statically-allocated thread. The single statically-allocated thread includes, for each procedure call that would otherwise introduce a new simulated thread, a memory block including (1) a relatively small procedure call stack for the new simulated thread, and (2) a relatively small collection of local variables and other state information for the new simulated thread.

Abstract: Maintenance of plural active file systems, wherein each of the active file systems initially access data shared with another of the active file systems, and wherein changes made to each of the active file systems are not reflected in other active file systems. When a second active file system is created based on a first active file system, the first active file system and the second active file system initially share data. When changes are made to the first active file system, modified data is recorded in the first active file system in a location that is not shared with the second active file system. When changes are made to the second active file system, modified data is recorded in the second active file system in a location that is not shared with the first active file system. Also, creation of the plural active file systems.

Abstract: The invention discloses methods and apparatus for broadcasting information across an interconnect that includes a plurality of nodes each connected to its adjacent node(s) using one or more links. The nodes can emit cells containing transaction sub-actions onto the links. As a node receives a cell the node retransmits the cell onto other links as the cell is being received. Thus, reducing the latency imposed by the node. The node also captures the transaction sub-action while it the cell is retransmitted. The node responds to the transaction sub-action by manipulating shared handshake lines that are bussed with the other nodes. The invention enables snooping cache protocols to be successfully used in a larger multi-processor computer system than the prior art.

Abstract: The invention provides flexible disabling of disk sets. One or more disks in a RAID subsystem may be identified as temporarily inactive. The disk or disks are then marked as inactive by setting one of a set of bits associated with each disk in the RAID subsystem. If an inactivated disk is a data disk, marking it as inactive also marks it as read only. If an inactivated disk is a parity disk, the RAID group to which it supplies parity is also inactivated and a file system must look to a mirror of the inactivated RAID subsystem for its data. When a data disk is reactivated it is marked as read/write by clearing its associated bit. When a parity disk is reactivated it is also marked as read/write by clearing its bit, however, it is not available for use until it has synchronized its operation with its mirror.