Abstract: Server computers may include one or more input/output (I/O) adapter devices for communicating with a network and/or direct-attached device. The I/O adapter device may implement processes to manage write requests in a general and flexible manner. The I/O adapter device may also implement processes to manage write requests in a fast an efficient—that is, low latency—manner. Low latency write requests processes may include determining that a write packet for a write request can be processed without additional assistance from a processor, once a processor has initiated a memory access request to fetch write data and also generated protocol information for transmitting the write packet. The I/O adapter device may then process and transmit the write packet through an offload pipeline, without interrupting a processor.

Abstract: Nuclear magnetic resonance apparatuses and methods for estimating properties of an earth formation are provided. An apparatus includes a carrier configured to be deployed in a borehole, at least one transmitting assembly configured to generate an oscillating magnetic field in a volume of interest within the earth formation, at least one receiving assembly configured to detect a nuclear magnetic resonance (NMR) signal originating in the volume of interest; and a magnet assembly configured to generate a static magnetic field in the formation from a primary side of the magnet assembly. The magnet assembly includes an array of longitudinally elongated magnets having a rotating pattern of magnetic orientations, the array configured to generate the static magnetic field in the volume of interest, and the static magnetic field strength is higher at the primary side than the field strength at a side of the magnet assembly that is opposite the primary side.

Abstract: The estimated rate of work requests expected during a time period at a first block storage device, implemented at a particular server of a storage service, exceeds a provisioned rate of the first device. At a client-side component of the storage service, a different storage server is identified, at which the rate of work requests directed during the time period to a second block storage device is anticipated to be less than the provisioned rate of the second device. At least one admission control parameter of the first device is modified to enable the first storage server to accept work requests at a rate that exceeds the provisioned rate of the first device.

Abstract: A nuclear magnetic resonance apparatus includes a magnet assembly, a transmitting antenna configured to generate an oscillating magnetic field in a sensitive volume within an earth formation, and one or more receiving antennas configured to detect a nuclear magnetic resonance signal originating in the sensitive volume. The one or more receiving antennas are arranged relative so that the one or more receiving antennas are inductively decoupled from the transmitting antenna, a first portion of the surface area of the one or more receiving antennas overlapping a first region of the transmitting antenna in which a magnetic flux of the transmitting antenna is in a first direction, and a second portion of the surface area of the one or more receiver antennas overlapping a second region of the transmitting antenna in which the magnetic flux is in a second direction predominantly opposed to the first direction.

Abstract: A user can set or modify operational parameters of a data volume stored on a network-accessible storage device in a data center. For example, the user may be provided access to a data volume and may request a modification to the operational parameters of the data volume. Instead of modifying the existing data volume, the data center can provision a new data volume and migrate data stored on the existing data volume to the new data volume. While the data migration takes place, the existing data volume may block input/output (I/O) requests and the new data volume may handle such requests instead. If a request is received for data not yet migrated to the new data volume, then the new data volume prioritizes a migration of the requested data.

Abstract: Systems and methods are described for a storage processing service that processes multiple storage commands. The storage processing service uses tags from test storage commands to determine whether a test storage service is to be instantiated that reflects a corresponding production service. Test storage commands with the same tag are tested on that test service. Additionally, the storage processing service determines a strategy for testing processes on production services when the storage system is overloaded. In one embodiment, the test service manager can determine to stop testing processes for a period of time, and issue a shed command that queues or sheds test storage commands. Advantageously, a shed command, while active at a storage processing service, may alleviate the overload on production services. The test service manager can continue to monitor the storage system to determine whether the overload continues to exist.

Abstract: The current document describes a storage system that provides a storage volume with a block-data interface to one or more clients. The storage system provides a key-value store that is associated with the storage volume. The clients access the key-value store via a key-value interface that provides a number of key-value operations to read, write, list, and delete key-value records from the key-value store. In some implementations, the key-value interface provides additional key-value operations that support the use of the key-value store by more than one client at a time. An environment in which the key-value store is used by the clients to retain I/O throttling parameters is described.

Abstract: A storage system may implement dynamic configuration of data volumes. Client utilization of a data volume in a storage system may be tracked or monitored. Based on the utilization of the data volume, configuration recommendations to reconfigure the data volume according to data volume offerings may be determined. The data volume may be configured according to an authorized configuration recommendation. In some embodiments, these recommendations may be provided to a client and selection of the configuration recommendation to perform may be received. In some embodiments, a configuration recommendation may be automatically performed based on previously provided authorization to configure the data volume.

Abstract: Method and apparatus contemplating a storage device communicating with a host via a bus, the storage device comprising programming instructions stored in memory that are configured to transmit a training signal that is not a COMWAKE signal to the host in response to receiving a COMWAKE signal from the host, after transmitting the training signal to the host then to determine whether a training signal is received from the host within a predetermined time interval, and if the training signal is received from the host within the predetermined time interval then transmitting a COMWAKE signal to the host.

Abstract: Systems and methods are described providing detailed input/output (I/O) metric information that is collected and gathered by an agent of the storage volume. An I/O request is received by a storage volume, and the agent associates primary and secondary identifiers with that I/O request. For example, a trace may be associated with that I/O request. The agent may store this I/O metric information in a ring buffer. Further, after collection and aggregation, statistics may be published by an I/O metric service that further processes the data provided by the agent. Advantageously, interdependent relationships associated with the I/O request or I/O operations of that request may be included in those statistics. This may allow an operator to evaluate the performance of I/O requests for a network.

Abstract: Server computers may include one or more input/output (I/O) adapter devices for communicating with a network and/or direct-attached device. The I/O adapter device may implement processes to manage write requests in a general and flexible manner. The I/O adapter device may also implement processes to manage write requests in a fast an efficient—that is, low latency—manner. Low latency write requests processes may include determining that a write packet for a write request can be processed without additional assistance from a processor, once a processor has initiated a memory access request to fetch write data and also generated protocol information for transmitting the write packet. The I/O adapter device may then process and transmit the write packet through an offload pipeline, without interrupting a processor.

Abstract: Server computers often include one or more input/output (I/O) devices for communicating with a network or directly attached storage device. Data transferred between these devices may include blocks of data with a common often repeated and identifiable data pattern. Transfer and storage of data of this nature may be optimized by transferring primarily blocks of data that are not of the pre-determined data pattern. An indicator may be transferred and stored with transferred data that has been reduced in size in this manner.

Abstract: A user can set or modify operational parameters of a data volume stored on a network-accessible storage device in a data center. For example, the user may be provided access to a data volume and may request a modification to the operational parameters of the data volume. Instead of modifying the existing data volume, the data center can provision a new data volume and migrate data stored on the existing data volume to the new data volume. While the data migration takes place, the existing data volume may block input/output (I/O) requests and the new data volume may handle such requests instead. If a request is received for data not yet migrated to the new data volume, then the new data volume prioritizes a migration of the requested data.

Abstract: A user can set or modify operational parameters of a data volume stored on a network-accessible storage device in a data center. For example, the user may be provided access to a data volume and may request a modification to the operational parameters of the data volume. Instead of modifying the existing data volume, the data center can provision a new data volume and migrate data stored on the existing data volume to the new data volume. While the data migration takes place, the existing data volume may block input/output (I/O) requests and the new data volume may handle such requests instead. Once the data migration is complete, the data center may deallocate the data blocks of the existing data volume such that the data blocks can be reused by other data volumes.

Abstract: Devices, methods and computer-readable media for controlling a device timeout parameter are disclosed. For example, a device receives a condition for modifying a timeout parameter and a modification. The device then detects the condition for modifying the timeout parameter and applies the modification to the timeout parameter in response to detecting the condition. A method determines a maximum time for a timeout parameter of a device and transmits a message to the device indicating the maximum time for the timeout parameter. A further method determines a condition for modifying a timeout parameter of a device and a modification. The method then transmits a message to the device indicating the condition for modifying the timeout parameter of the device and the modification.

Abstract: A network-based storage resource may implement access control for virtual computing resources that utilize the storage resource during live migration of the virtual computing resources. A network-based storage resource may enforce an access control that limits access to a host of a virtual compute instance. Upon detecting migration of the virtual compute instance, the network-based storage resource may allow a connection to be established with a destination host for the virtual compute instance. The access control mechanism may be updated to limit access to the destination host for data stored for the virtual compute instance at the network-based storage resource.

Abstract: Techniques are described for formally expressing whether sequences of operations performed on block storage devices are sequential or random. In embodiments, determinations of whether these sequences of operations are sequential or random may be used to predict latencies involved with running particular workloads, and to predict representative workloads for particular latencies.

Abstract: Server computers often include one or more input/output (I/O) adapter devices for communicating with a network or directly attached storage device. The data transfer latency for request can be reduced by utilizing ingress data placement logic to bypass the processor of the I/O adapter device. For example, host memory descriptors can be stored in a content addressable memory unit of the I/O adapter device to facilitate placement of requested data.

Abstract: Techniques for preserving the state of virtual machine instances during a migration from a source location to a target location are described herein. A set of credentials configured to provide access to a storage device by a virtual machine instance at the source location is provided to the virtual machine instance. When the migration from the source location to the target location starts, a second set of credentials configured to provide access to a storage device by a virtual machine instance at the source location is provided to the virtual machine instance. During the migration, a response to an input-output request is provided to one or more of the locations using the set of credentials and based at least in part on the state of the migration.

Abstract: Systems and methods are described for dynamically detecting outliers in a set of input/output (I/O) metrics collected and aggregated by a storage volume network. An I/O request is received by a storage volume network, and an agent of the storage volume network associates primary and secondary identifiers with that I/O request. For example, a trace may be associated with a request to write data to a storage volume network, and spans may be associated with the individual operations required to fulfill that request. Once gathered, I/O metrics may be aggregated based on the associated identifiers. I/O metric information regarding outliers may be received from the storage volume network, processed, and published by an I/O metrics service to identify the outliers among the primary and secondary identifiers. These outliers may then be stored for further analysis, and may be utilized to determine improvements to the performance of a storage volume network.