Abstract: Resources of a deduplicated storage appliance are monitored to generate a consumption matrix indicating resource utilization. A threshold map associated with a subsystem is accessed. The subsystem is responsible for an operation involving files stored in the appliance. The threshold map specifies resources required by the subsystem for the operation and thresholds below which multi-streaming for the operation is allowed. An assessment is made as to whether the operation should be handled by multi-streaming. The assessment includes determining whether the resources are underutilized or overutilized based on the consumption matrix and the threshold map. When the resources are overutilized, multi-streaming is not triggered. When the resources are underutilized, multi-streaming is triggered. Periodic reassessments are made to determine whether the operation should be handled by multi-streaming.

Abstract: Cloud units in cloud storage include containers including data containers storing file segments, segment tree containers storing upper-level segments of segment trees representing the files, and cloud containers storing headers from the data and segment tree containers. A header for a data container includes fingerprints identifying the file segments. A header for a segment tree container includes fingerprints identifying the upper-level segments. A storage appliance stores a first level of metadata for each cloud unit in a read-write state, a second level of metadata for each cloud unit in a read-only state, and a third level of metadata for each cloud unit in an offline state. The third level requires less storage than the first and second levels. The second level requires less storage than the first level. The limited metadata space of the appliance is managed by maintaining at least a subset of cloud units in the read-only state.

Abstract: Data migrated from a deduplicated storage appliance are stored as cloud units at cloud storage. Each cloud unit includes containers including data containers storing segments of files, segment tree containers storing upper-level segments of segment trees representing the files, and cloud containers storing headers from the data and segment tree containers. A header for a data container includes fingerprints identifying the segments of files. A header for a segment tree container includes fingerprints identifying the upper-level segments. The cloud units are maintained in different states of accessibility including read-write, read-only, and offline. Upon detecting that local storage of the appliance does not have space to support a cloud unit in a read-write or read-only state, another cloud unit that is in a first state is selected, the first state being the read-write or read-only state. The selected cloud unit is placed in a second state, different from the first state.

Abstract: Containers are generated including data containers storing segments of files, segment tree containers storing upper-level segments of segment trees representing the files, and cloud containers storing headers from the data and segment tree containers. A header for a data container includes fingerprints identifying the segments of files. A header for a segment tree container includes fingerprints identifying the upper-level segments. The containers are sent to cloud storage for storage as a cloud unit. The cloud unit is attached to a deduplicated storage appliance by storing at the appliance the segment tree and cloud containers, cloud configuration details, and an index. The cloud configuration details identify the cloud storage having the cloud unit. The index maps the fingerprints to the containers. When a cloud unit is to be detached, the segment tree and cloud containers, and index from the local storage are deleted, but the cloud configuration details are maintained.

Abstract: The disclosure provides a system, computer readable medium, and computer-implemented method for managing data access. The method includes obtaining a data access request from a requestor for client data redundantly stored in at least two storage providers that are unknown to the requestor; identifying a service level objective for servicing the data access request; ranking the at least two storage providers based on the service level objective to identify one of the at least two storage providers to service the data access request; and providing the requestor with access to a copy of the client data using the one of the at least two storage providers.

Abstract: Resources of a deduplicated storage appliance are monitored to generate a consumption matrix indicating resource utilization. A threshold map associated with a subsystem is accessed. The subsystem is responsible for an operation involving files stored in the appliance. The threshold map specifies resources required by the subsystem for the operation and thresholds below which multi-streaming for the operation is allowed. An assessment is made as to whether the operation should be handled by multi-streaming. The assessment includes determining whether the resources are underutilized or overutilized based on the consumption matrix and the threshold map. When the resources are overutilized, multi-streaming is not triggered. When the resources are underutilized, multi-streaming is triggered. Periodic reassessments are made to determine whether the operation should be handled by multi-streaming.

Abstract: Various embodiments of the teachings herein include a power converter to convert between a first, AC voltage and a second voltage. An example includes: half-bridges connected in parallel, each comprising two semiconductor switches connected serially with outer terminals of the half-bridge forming terminals for the second voltage; a filter connected between midpoints of the half-bridges and terminals for the first voltage, comprising an inductor and a capacitor; a sensor for each half-bridge to measure current flowing between the midpoints of the half-bridges and the filter circuit; and a control circuit to operate the switches. The control circuit determines switching times using a modified reference voltage signal resulting in a softened bus clamp modulation. A controller creates the modified reference voltage signal using an unmodified reference voltage signal as a setpoint input and a sum of the current signals from the current sensors as measured input.

Abstract: Prioritization in cloud migration for deduplication systems is described. A system creates a set of priorities corresponding to backup files in a set of backup files, wherein each priority is based on estimating a time required for a corresponding backup file to migrate from a local storage system to a cloud storage system, and/or an amount of data deduplicated when the corresponding backup file is stored. The system copies a backup file, which corresponds to the highest priority in the set of priorities, from the set of backup files stored in the local storage system to a cloud storage system. Completing the copying of the set of backup files to the cloud storage system, the system copies a backup file, which corresponds to the lowest priority in the set of priorities, from the set of backup files stored in the local storage system to a cloud storage system.

Abstract: Described is a system (and method) for efficient metadata verification when leveraging multi-streams as part of data deduplication system. The system may efficiently perform metadata integrity verification by dynamically invoking multi-streaming to leverage parallelization for metadata verification. Accordingly, the system may better utilize bandwidth and processing capabilities to reduce verification time.

Abstract: Described is a system (and method) for efficient metadata verification when leveraging multi-streams as part of data deduplication system. The system may efficiently perform metadata integrity verification by dynamically invoking multi-streaming to leverage parallelization for metadata verification. Accordingly, the system may better utilize bandwidth and processing capabilities to reduce verification time.

Abstract: The disclosure provides a system, computer readable medium, and computer-implemented method for managing data access. The method includes obtaining a data access request from a requestor for client data redundantly stored in at least two storage providers that are unknown to the requestor; identifying a service level objective for servicing the data access request; ranking the at least two storage providers based on the service level objective to identify one of the at least two storage providers to service the data access request; and providing the requestor with access to a copy of the client data using the one of the at least two storage providers.

Abstract: Embodiments for performing data recovery from cloud storage to a backup appliance that goes from an offline state to an online state, including identifying super metadata among metadata stored in the cloud storage for the backup appliance, wherein the super metadata comprises an amount on the order of ten percent of the metadata representing a minimum amount of information to reconstruct the metadata, copying the super metadata blocks from the cloud storage to local metadata storage of the backup appliance while it is in the offline state to leave remaining metadata, and copying the remaining metadata blocks from the cloud storage to the local metadata storage while the backup appliance is in the online state.

Abstract: Embodiments for performing data recovery from cloud storage to a backup appliance that goes from an offline state to an online state, including identifying super metadata among metadata stored in the cloud storage for the backup appliance, wherein the super metadata comprises an amount on the order of ten percent of the metadata representing a minimum amount of information to reconstruct the metadata, copying the super metadata blocks from the cloud storage to local metadata storage of the backup appliance while it is in the offline state to leave remaining metadata, and copying the remaining metadata blocks from the cloud storage to the local metadata storage while the backup appliance is in the online state.

Abstract: Various embodiments include an inductor assembly for a converter comprising: a plurality of first conductors arranged on respective legs of a first magnetic core; a second magnetic core with one or more legs, the second core magnetically coupled to the first core via an air-gap and arranged to provide a path for common mode magnetic flux of the plurality of first conductors; and a respective second conductor corresponding to each of the plurality of first conductors. Each pair of first and second conductors is electrically connected in series. The second conductors are arranged on a single leg of the second core and positively coupled to each other.

Abstract: Various embodiments include an inductor assembly for a converter comprising: a plurality of first conductors arranged on respective legs of a first magnetic core; a second magnetic core with one or more legs, the second core magnetically coupled to the first core via an air-gap and arranged to provide a path for common mode magnetic flux of the plulrality of first conductors; and a respective second conductor corresponding to each of the plurality of first conductors. Each pair of first and second conductors is electrically connected in series. The second conductors are arranged on a single leg of the second core and positively coupled to each other.

Abstract: A converter module for a modularly configured inverter may include: a first and a second module terminal each having a positive contact, a negative contact, and a reference potential contact; a first semiconductor switch connected to the positive contacts; a second semiconductor switch connected to the negative contacts; an inductor connected to the reference potential contacts; a first series circuit comprising a third switch and a capacitor in parallel to the first switch; and a second series circuit comprising a fourth switch and a second capacitor in parallel to the second switch.

Abstract: The present disclosure relates to converter modules. The teachings thereof may be embodied in converter modules for a multi-level energy converter. For example, a method for operating a converter module of a multi-level energy converter by means of a control unit and via a control connection may include: controlling the switching states of one of two converter module connections of the converter module and a switching unit incorporating the control connection. Two series-connected converter module capacitors connected to the switching unit respectively deliver a converter module capacitor voltage. The switching unit switches the converter module capacitor voltage of one of the converter module capacitors or a summed voltage of the series-connected converter module capacitors to the converter module connections, according to the respective switching state of the switching unit.

Abstract: A converter with a DC link for converting an input voltage into an alternating voltage with a pre-determined amplitude and frequency for driving a single or multiple-phase load may include a number of modules which are stackable over one another. Each module may have a ceramic cooling body with a receiving surface on which electronic components of one phase are mounted, wherein the ceramic cooling body has channel(s) in the region of the receiving surface for carrying a coolant during the operation of the converter The converter may include a DC link capacitor and input-side and output-side power connections arranged on a first carrier having a arranged perpendicular to the receiving surface. The converter may also include a control unit for driving the electronic components of the phase, the control unit being arranged on a second carrier having a main plane arranged perpendicularly to the plane of the receiving surface.

Abstract: The present disclosure relates to converter modules. The teachings thereof may be embodied in converter modules for a multi-level energy converter. For example, a method for operating a converter module of a multi-level energy converter by means of a control unit and via a control connection may include: controlling the switching states of one of two converter module connections of the converter module and a switching unit incorporating the control connection. Two series-connected converter module capacitors connected to the switching unit respectively deliver a converter module capacitor voltage. The switching unit switches the converter module capacitor voltage of one of the converter module capacitors or a summed voltage of the series-connected converter module capacitors to the converter module connections, according to the respective switching state of the switching unit.

Abstract: A converter with a DC link for converting an input voltage into an alternating voltage with a pre-determined amplitude and frequency for driving a single or multiple-phase load may include a number of modules which are stackable over one another. Each module may have a ceramic cooling body with a receiving surface on which electronic components of one phase are mounted, wherein the ceramic cooling body has channel(s) in the region of the receiving surface for carrying a coolant during the operation of the converter The converter may include a DC link capacitor and input-side and output-side power connections arranged on a first carrier having a arranged perpendicular to the receiving surface. The converter may also include a control unit for driving the electronic components of the phase, the control unit being arranged on a second carrier having a main plane arranged perpendicularly to the plane of the receiving surface.