Abstract: A photovoltaic DC power distribution system provides a DC-DC converter having an output serially connected between a photovoltaic module array and a power converter, such as an inverter, in which the input voltage to the power converter is the sum of the voltage from the array and a voltage output of the DC-DC converter. The DC-DC converter only handles a portion of the power transferred from the array to the power converter.

Abstract: A system is disclosed for extracting a medium DC voltage from a plurality of PV modules arranged in an array and supplying the medium DC voltage to inverters located outside the array near a point of interconnection with a utility grid.

Abstract: A photovoltaic DC power distribution system provides a DC-DC converter having an output serially connected between a photovoltaic module array and a power converter, such as an inverter, in which the input voltage to the power converter is the sum of the voltage from the array and a voltage output of the DC-DC converter. The DC-DC converter only handles a portion of the power transferred from the array to the power converter.

Abstract: A system is disclosed for extracting a medium DC voltage from a plurality of PV modules arranged in an array and supplying the medium DC voltage to inverters located outside the array near a point of interconnection with a utility grid.

Abstract: Methods and apparatus involve booting a computing device from a flash device. The flash device has memory partitions, including a read-only and a read/write partition. The read-only includes an operating system for use by the computing device and defines an initial system state. The read/write is configured to store a delta from the initial system state. Upon booting the computing device subsequent to an initial boot, the delta and the initial system state together define the whole system state. In other features, a write engine from the read-only partition tracks changes to the initial system state and writes some, but not all of the changes back to the read/write partition thereby minimizing a number of writes to the flash memory. In this manner, the speed of the flash memory can be used to quickly boot/reboot a computing device, while avoiding the wear limits associated with writing to flash devices.

Abstract: A method for detecting and resolving a partition condition in a cluster of computers in a networked environment is described. In one example, the method includes creating a scratch pad area and dividing the scratch pad into slots. Each slot is associated with a node within the cluster. A generation number and a list of known nodes are recorded in each slot when a change of membership occurs in the cluster. The slots are compared to ensure the generation number and the list of known nodes matches in each slot, and the partition condition is resolved by creating a list of surviving nodes and re-allocating appropriate resources to each of the surviving nodes.

Abstract: Methods and apparatus involve providing computing backup for virtual representations on a physical hardware platform without the attendant overhead of an installed backup agent per each of the virtual representations. Representatively, a hardware platform has a processor and memory upon and a plurality of virtual machines are configured on the processor and memory as guest computing devices by way of scheduling control of a hypervisor layer. A common I/O path between the virtual machines and the hardware platform exists in the hypervisor layer and a single backup agent for the entirety of the virtual machines monitors data flows in the common I/O path. In this way, each virtual machine avoids dedicated backup agents, and their attendant overhead, especially by avoiding backup agents configured uniquely per a guest operating system, a guest file system, etc. Some other features contemplate particular I/O paths, operating systems, hypervisors, domains, and computer program products.

Abstract: Methods and apparatus involve managing a plurality of hardware platforms with common tools despite actual or potential non-uniformity of vendor items. Representatively, hardware platforms include a minimalist operating system upon which a management agent and vendor-specific providers are deployed. From a console common to the platforms, local or remote management occurs. In a paradigm shift when initially deploying or redeploying platforms, for example, a “just enough” operating system exists to configure the hardware of different vendors so virtual machines can be thereafter deployed without needing pre-configured operating systems, bundled management packages, etc. A common embedded hypervisor on the platform is but one technique to achieve a minimalist operating system as is a common CIMOM or SNMP agent but one technique to achieve a management agent. Other features include computing systems and computer program products, to name a few.

Abstract: Methods and apparatus involve booting a computing device from a flash device. The flash device has memory partitions, including a read-only and a read/write partition. The read-only includes an operating system for use by the computing device and defines an initial system state. The read/write is configured to store a delta from the initial system state. Upon booting the computing device subsequent to an initial boot, the delta and the initial system state together define the whole system state. In other features, a write engine from the read-only partition tracks changes to the initial system state and writes some, but not all of the changes back to the read/write partition thereby minimizing a number of writes to the flash memory. In this manner, the speed of the flash memory can be used to quickly boot/reboot a computing device, while avoiding the wear limits associated with writing to flash devices.

Abstract: Methods and apparatus involve file systems for virtual machines and image deltas. Representatively, a plurality of virtual machines are configured on a hardware platform and a file system includes both a read-only portion and a writable portion that together provides the entire file system for each virtual machine. Also, a union of the two portions provides an incremental snapshot of its corresponding virtual machine and can be used to restore the virtual machine upon a failure event. In content, the read-only portion contains substantially immutable information such as core basic system image, while the writable portion contains configuration information, state data and production information. An available storage device for the virtual machines is partitioned for each virtual machine and its corresponding writable portion is found therein. Other features contemplate particular configurations and computer program products, to name a few.

Abstract: Methods and apparatus restore data on servers in remote or branch offices utilizing virtual distribution components, such as virtual machines. A failed remotely located server is restored to its previous running state using any server with hardware compatible with the hardware of the failed server, rather than requiring a server with an exact copy of the hardware of the failed server. Virtual distribution components are configured without requiring a reimaging of the entire boot partition and physical distribution partition of a physical server. Application environment state information is restored without requiring a restoration of a full operating system state environment. Constantly supported interfaces of physical distribution components are utilized and a quick restoration of virtual distribution components results. Full system functionality is achieved more quickly than when a full physical system image restoration is required.

Abstract: Methods and apparatus involve providing computing backup for virtual representations on a physical hardware platform without the attendant overhead of an installed backup agent per each of the virtual representations. Representatively, a hardware platform has a processor and memory upon and a plurality of virtual machines are configured on the processor and memory as guest computing devices by way of scheduling control of a hypervisor layer. A common I/O path between the virtual machines and the hardware platform exists in the hypervisor layer and a single backup agent for the entirety of the virtual machines monitors data flows in the common I/O path. In this way, each virtual machine avoids dedicated backup agents, and their attendant overhead, especially by avoiding backup agents configured uniquely per a guest operating system, a guest file system, etc. Some other features contemplate particular I/O paths, operating systems, hypervisors, domains, and computer program products.

Abstract: A method and system to detect and resolve a partition condition in a cluster of computers in a networked environment is described. The method can include: creating a scratch pad area accessible by the cluster of computers; dividing the scratch pad into a plurality of slots; recording in the plurality of slots, a generation number and a list of known nodes by each one of the plurality of notes, wherein an identifier is written in the list for each node that is known to a writing node; comparing each slot of the plurality of slots to ensure the generation number and the list of known nodes matches in each slot of the plurality of slots; and resolving the partition condition by creating a list of surviving nodes and re-allocating appropriate resources to each of the surviving nodes.