Abstract: A method is provided to allow a user on a host system to update a specific snapshot in a data storage system where the user does not have other editing privileges. The method includes (1) receiving a request to update the snapshot from the user and (2) determining from an access control list if the user is permitted to update the snapshot. If the user is permitted to update the snapshot, the method includes (3) recording parameters for a VLUN (virtual logic unit) associated with the snapshot, (4) removing the VLUN from the data storage system, (5) replacing the snapshot with a new snapshot created from a parent volume of the snapshot, (6) recreating the VLUN for the new snapshot from the recorded parameters, and (7) exporting the VLUN to the host system.

Abstract: A method for recovering natural gas from a group of subterranean zones containing natural gas, including injecting an amount of a displacing gas into a first subterranean zone, producing a first produced gas from the first subterranean zone, collecting an amount of the first produced gas wherein the quality of the collected first produced gas is higher than or equal to a threshold production quality for the first produced gas, injecting an amount of the first produced gas into a second subterranean zone wherein the quality of the injected first produced gas is higher than or equal to a threshold injection quality for the first produced gas, producing a second produced gas from the second subterranean zone, and collecting an amount of the second produced gas wherein the quality of the collected second produced gas is higher than or equal to a threshold production quality for the second produced gas.

Abstract: A communication link protocol is provided for communicating between nodes of an interconnect system via a communication link. In one embodiment, the communication link protocol includes a direct memory access (DMA) command for writing a block of data from a local node to a remote node via the communication link; an administrative write command for writing data from a local node to registers in a remote node via the communication link for administrative purposes; a memory copy write command for writing a line of memory from a local node to a remote node via the communication link when any data is written into that line of memory; and a built in self test (BIST) command for testing the functionality of the communication link.

Abstract: A method for recovering natural gas from a group of subterranean zones containing natural gas, including injecting an amount of a displacing gas into a first subterranean zone, producing a first produced gas from the first subterranean zone, collecting an amount of the first produced gas wherein the quality of the collected first produced gas is higher than or equal to a threshold production quality for the first produced gas, injecting an amount of the first produced gas into a second subterranean zone wherein the quality of the injected first produced gas is higher than or equal to a threshold injection quality for the first produced gas, producing a second produced gas from the second subterranean zone, and collecting an amount of the second produced gas wherein the quality of the collected second produced gas is higher than or equal to a threshold production quality for the second produced gas.

Abstract: A node controller for a data storage system having at least one node provides access to a data storage facility. The node controller is distinct from a computer-memory complex of the node. The node controller provides overall control for transferring data through the node.

Abstract: A method is provided for a data storage system to move data from a source logical disk (LD) region to a target LD region while the data storage system remains online to a host. The method includes determining if a region move will create excessive load so the data storage system appears offline to the host. If not, the method includes causing writes to the source LD region to be mirrored to the target LD region, causing data in the source LD region to be copied to the target LD region, blocking reads and writes to the data storage system, and flushing dirty cache in the data storage system. If flushing the dirty cache is fast so the data storage system appears online to the host, the method includes updating mappings of the virtual volume to the LD regions and resuming the reads and writes to the data storage system.

Abstract: A method is provided for a data storage system to change the RAID type, the layout characteristics, and the performance characteristics of a virtual volume mapped to logical disk regions in one or more logical disks while the data storage system remains online to a host. Another method is provided for a data storage system to consolidate space in one or more logical disks mapped to a virtual volume while the data storage system remains online to a host. The one or more logical disks can be consolidated to free unused chunklet regions for use in other logical disks.

Abstract: A modified toe-to-heel waterflooding (TTHW) process is provided for recovering oil from a reservoir in an underground formation. After establishing the conventional TTHW waterflood, the process includes placing a chemical blocking agent at the watered out producing toe portion of the horizontal leg of the production well to create a blockage in the producing toe portion and to create a new producing toe portion in an open portion of the horizontal leg adjacent the blockage through which most of the production takes place. Production is then continued through the new producing toe portion and the open portion of the horizontal leg of the production well. These blocking and producing steps can be continued to progressively block producing toe portions in a direction toward the vertical pilot portion of the production well.

Abstract: A multiprocessor computer system is configured to selectively transmit address transactions through an address network using either a broadcast mode or a point-to-point mode transparent to the active devices that initiate the transactions. Depending on the mode of transmission selected, either a directory-based coherency protocol or a broadcast snooping coherency protocol is implemented to maintain coherency within the system. A computing node is formed by a group of clients which share a common address and data network. The address network is configured to determine whether a particular transaction is to be conveyed in broadcast mode or point-to-point mode. In one embodiment, the address network includes a mode table with entries which are configurable to indicate transmission modes corresponding to different regions of the address space within the node.

Abstract: A modified toe-to-heel waterflooding (TTHW) process is provided for recovering oil from a reservoir in an underground formation. After establishing the conventional TTHW waterflood, the process includes placing a chemical blocking agent at the watered out producing toe portion of the horizontal leg of the production well to create a blockage in the producing toe portion and to create a new producing toe portion in an open portion of the horizontal leg adjacent the blockage through which most of the production takes place. Production is then continued through the new producing toe portion and the open portion of the horizontal leg of the production well. These blocking and producing steps can be continued to progressively block producing toe portions in a direction toward the vertical pilot portion of the production well.

Abstract: A method is provided for a data storage system to change the RAID type, the layout characteristics, and the performance characteristics of a virtual volume mapped to logical disk regions in one or more logical disks while the data storage system remains online to a host. Another method is provided for a data storage system to consolidate space in one or more logical disks mapped to a virtual volume while the data storage system remains online to a host. The one or more logical disks can be consolidated to free unused chunklet regions for use in other logical disks.

Abstract: A method is provided for a data storage system to move data from a source logical disk (LD) region to a target LD region while the data storage system remains online to a host. The method includes determining if a region move will create excessive load so the data storage system appears offline to the host. If not, the method includes causing writes to the source LD region to be mirrored to the target LD region, causing data in the source LD region to be copied to the target LD region, blocking reads and writes to the data storage system, and flushing dirty cache in the data storage system. If flushing the dirty cache is fast so the data storage system appears online to the host, the method includes updating mappings of the virtual volume to the LD regions and resuming the reads and writes to the data storage system.

Abstract: A multiprocessor computer system to selectively transmit address transactions using a broadcast mode or a point-to-point mode. Either a directory-based coherency protocol or a broadcast snooping coherency protocol is implemented to maintain coherency. A node is formed by a group of clients which share a common address and data network. The address network determines whether a transaction is conveyed in broadcast mode or point-to-point mode. The address network includes a table with entries which indicate transmission modes corresponding to different regions of the address space within the node. Upon receiving a coherence request transaction, the address network may access the table to determine the transmission mode which corresponds to the received transaction. Network congestion may be monitored and transmission modes adjusted accordingly. When network utilization is high, the number of transactions which are broadcast may be reduced.

Abstract: A method is provided for communicating data in an interconnect system comprising a plurality of nodes. In one aspect, the method includes: issuing a command packet from a first node, the command packet comprising a respective header quadword and at least one respective data quadword for conveying a command to a second node, wherein the command is selected from a group comprising a direct memory access (DMA) command, an administrative write command, a memory copy write command, and a built in self test (BIST) command; receiving the command packet at the second node; issuing an acknowledgement packet from the second node, the acknowledgement packet comprising a respective header quadword for conveying an acknowledgement that the command packet has been received at the second node.

Abstract: A system may include a plurality of nodes coupled by an inter-node network. Each of the nodes includes several active devices, an interface to the inter-node network, and an address network coupling the active devices to the interface. An active device included in one of the nodes initiates a transaction by sending either a first type of address packet or a second type of address packet on the address network dependent on whether the active device is included in a multi-node system. The first type of address packet is sent if the active device is included in a multi-node system and is not snooped by other active devices in the same node as the active device. The second type of address packet, sent if the active device is included in a single node system, is snooped by other active devices in the same node as the active device.

Abstract: A multiprocessor computer system is configured to selectively transmit address transactions through an address network using either a broadcast mode or a point-to-point mode transparent to the active devices that initiate the transactions. Depending on the mode of transmission selected, either a directory-based coherency protocol or a broadcast snooping coherency protocol is implemented to maintain coherency within the system. A computing node is formed by a group of clients which share a common address and data network. The address network is configured to determine whether a particular transaction is to be conveyed in broadcast mode or point-to-point mode. In one embodiment, the address network includes a mode table with entries which are configurable to indicate transmission modes corresponding to different regions of the address space within the node.

Abstract: A data storage system includes a plurality of nodes for providing access to a data storage facility. Each node has a computer-memory complex to provide general purpose computing for the node, a node controller to control data transfers through the respective node, and a cluster memory to buffer data for the data transfers. A plurality of communication paths interconnect the nodes, with a separate communication path provided for each two nodes of the data storage system.

Abstract: A node controller for a data storage system having at least one node provides access to a data storage facility. The node controller is distinct from a computer-memory complex of the node. The node controller provides overall control for transferring data through the node.

Abstract: A probabilistic queue lock divides requesters for a lock into at least three sets. In one embodiment, the requesters are divided into the owner of the lock, the first waiting contender, and the other waiting contenders. The first waiting contender is made probabilistically more likely to obtain the lock by having it spin faster than the other waiting contenders. Because the other waiting contenders spin more slowly, the first waiting contender is more likely to be able to observe the free lock and acquire it before the other waiting contenders notice that it is free. The first of the other waiting contenders that determines that the previous first waiting contender has acquired the lock is promoted to be the new first waiting contender and begins spinning fast. Because only the first waiting contender is spinning fast on the lock, it is probable that only the first waiting contender will attempt to acquire the lock when it becomes available.

Abstract: A method is provided for communicating data in an interconnect system comprising a plurality of nodes. In one aspect, the method includes: issuing a command packet from a first node, the command packet comprising a respective header quadword and at least one respective data quadword for conveying a command to a second node, wherein the command is selected from a group comprising a direct memory access (DMA) command, an administrative write command, a memory copy write command, and a built in self test (BIST) command; receiving the command packet at the second node; issuing an acknowledgement packet from the second node, the acknowledgement packet comprising a respective header quadword for conveying an acknowledgement that the command packet has been received at the second node.