Abstract: Systems and methods are provided for management of data access latency in a distributed storage system by dynamically replicating data objects experiencing a high request volume. When a storage node is unable to meet a data access latency target (e.g., due to one or more data objects hosted by the storage node being the subject of a large quantity of requests), the storage node may initiate a process by which a second storage node is employed to reduce the request processing load. The second storage node may cache a copy of the requested data object, and may service at least a portion of requests for the data object using the cached copy.

Abstract: Systems and methods are provided for implementing a multi-service file system for a hosted computing instance via a locally-addressable secure compute layer. Software within the instance can submit file operations to the secure compute layer, which the secure compute layer can translate into calls to one or more network-accessible storage services. To provide a multi-service file system, the secure compute layer can obtain mapping data mapping file system objects within the virtualized file system to different network-accessible storage services. On receiving a file operation, the secure compute layer can determine one or more network-accessible storage services corresponding to the file operation, and submit appropriate calls to the one or more network-accessible storage services.

Abstract: An object compression system of a storage service may provide a user-friendly and cost-efficient solution to manage stored objects for users of the storage service. The object compression system may automatically monitor individual objects in an object-based storage system of the storage service. Based on one or more characteristics and additional features of the objects, the object compression system may generate respective determinations whether to compress the individual objects. Responsive to determinations to compress the objects, the object compression system may determine compression algorithms for individual objects. The object compression system may compress the objects according to respective compression algorithms to create compressed files. The object compression system may store the compressed files in a tier different from the objects and delete the objects from the storage service.

Abstract: Systems and methods are provided for exposing disparate storage systems and technologies to compute instances through a unified file system interface that is agnostic to the underlying storage systems and technologies. A file system namespace service may provide the ability to compose a file system from different storage technologies and systems (e.g., block storage, object storage, etc.). The file system namespace service may also provide the ability to layer different storage services (e.g., by treating local block storage volume as a write back cache, by treating a file system as a read-through cache in front of an object storage service, etc.), and/or the ability to bind virtual files to other compute instances and/or storage systems.

Abstract: Technologies are provided for supporting multi-actuator storage device access using logical addresses. Separate sets of storage locations on a storage medium of a storage device can be associated with different actuators of the storage device. For example, a first set of storage locations can be assigned to a first actuator of the storage device and a second set of storage locations can be assigned to a second actuator of the storage device. The storage locations of the storage medium can be associated with logical addresses. The storage device can receive a data access request containing a logical address and can identify a storage location associated with the logical address. The storage device can identify a storage location set to which the storage location belongs and can use an actuator associated with the storage location set to access the storage location associated with the logical address.

Abstract: Technologies are provided for supporting multi-actuator storage device access using logical addresses. Separate sets of logical addresses (such as logical block addresses) can be associated with different actuators of a storage device. For example, a first set of logical addresses can be assigned to storage locations on one or more storage media that is/are accessible using a first actuator of the storage device and a second set of logical addresses can be assigned to storage locations on one or more storage media that is/are accessible using a second actuator of the storage device. The storage device can receive a data access request containing a logical address and can identify a logical address set to which the logical address belongs. The storage device can use an actuator associated with the logical address set to access a storage location assigned to the logical address.

Abstract: A device includes an interposer card that includes a processor, such as a system on a chip (SoC), and memory devices. The interposer card mounts to a mass storage device and has a shape that corresponds to a size of an end of the mass storage device to which the interposer card is mounted. The SoC of the interposer card is configured to implement an individual server for the mass storage device to which the interposer card is mounted. In some embodiments, a data storage system includes multiple mass storage devices mounted in a chassis and coupled to one or more backplanes, wherein interposer cards are connected between the mass storage devices and the one or more backplanes.

Abstract: A set of data units associated with a data object is obtained, such that respective instances of the data object can be reconstructed from respective subsets of the set. Corresponding to a request for the data object, a first subset of the set is identified. The first subset meets a uniqueness criterion with respect to other subsets of the set that are used to respond to other requests for the data object. An instance of the data object is reconstructed from the first subset.

Abstract: Technologies are provided for supporting storage device write barriers. A host computer can be configured to transmit a write barrier command to a storage device to indicate that one or more data access commands should be processed before one or more other data access commands are processed. For example, a host computer can transmit one or more data access commands to a storage device. The host computer can then transmit a write barrier command to the storage device. The storage device can be configured to receive the write barrier command and to associate a write barrier with the one or more data access commands. The host computer can continue to transmit additional data access commands to the storage device. However, the storage device will not process the additional data access commands until after the one or more data access commands associated with the write barrier have been processed.

Abstract: A device includes an interposer card that includes a processor, such as a system on a chip (SoC), and memory devices. The interposer card mounts to a mass storage device and has a shape that corresponds to a size of an end of the mass storage device to which the interposer card is mounted. The SoC of the interposer card is configured to implement an individual server for the mass storage device to which the interposer card is mounted. In some embodiments, a data storage system includes multiple mass storage devices mounted in a chassis and coupled to one or more backplanes, wherein interposer cards are connected between the mass storage devices and the one or more backplanes.

Abstract: Technologies are provided for supporting storage device write barriers. A storage device can be configured to associate a data access command with a write barrier. The write barrier can be used to indicate that one or more data access commands should be processed before one or more other data access commands are processed. For example, a host computer can transmit one or more data access commands to a storage device. The storage device can determine that the one or more data access commands are associated with a write barrier. The host computer can continue to transmit additional data access commands to the storage device. However, the storage device will not process the additional data access commands until after the one or more data access commands associated with the write barrier have been processed.

Abstract: Described are systems and methods for storing a data object using a hierarchical erasure encoding to store a physical representation of the data object across a plurality of fault domains. A first erasure encoding is applied to the data object to generate a first set of shards of the data object. Individual shards of the set of shards may then be distributed across the fault domains for storage. Within the fault domains a second erasure encoding may be applied to the individual shards to generate a second set of shards. Finally, a manifest may be generate in order to reconstruct the data object from the first set of shards and the second set of shards.

Abstract: Technologies are provided for accessing a physical location of a storage medium reader of a storage device. A computing device can transmit a request for the storage medium reader's physical location. The storage device can determine the physical location of the storage medium reader and transmit the location to the computing device. The computing device can use the physical location of the storage medium reader to determine an expected latency for retrieving one or more stored data items. The computing device can transmit a command to change the physical location of the storage medium reader, for example by changing a location of the storage medium reader with respect to a given storage medium and/or changing a storage medium that is accessed by the storage medium reader. The computing device can control the placement of the storage medium reader in order to optimize retrieval of data items from the storage device.

Abstract: A multi-actuator storage device includes separate actuators that can be used to access a storage medium. A property of a request can be analyzed to determine which actuator to use to access data associated with the request. For example, high-priority requests can be handled by an actuator designated for random I/O requests, whereas low-priority requests can be handled by an actuator designated for sequential I/O requests. Writes can be treated as low-priority requests. In a particular embodiment, a priority bit can be used to determine which actuator is used to access the data.

Abstract: A system for controlling, by a hypervisor, access to physical resources during execution of a virtual machine includes a physical disk and a hypervisor. The physical disk is provided by a computing device and stores at least a portion of a virtual disk. The hypervisor executes on the computing device. The hypervisor allocates, to the virtual disk, an amount of access to the physical disk. The hypervisor determines that a level of utilization of the physical disk has exceeded a threshold. The hypervisor limits, in response to the determination, access by the virtual disk to the physical disk.

Abstract: A system for controlling, by a hypervisor, access to physical resources during execution of a virtual machine includes a physical disk and a hypervisor. The physical disk is provided by a computing device and stores at least a portion of a virtual disk. The hypervisor executes on the computing device. The hypervisor allocates, to the virtual disk, an amount of access to the physical disk. The hypervisor determines that a level of utilization of the physical disk has exceeded a threshold. The hypervisor limits, in response to the determination, access by the virtual disk to the physical disk.

Abstract: A system for controlling, by a hypervisor, access to physical resources during execution of a virtual machine includes a physical disk and a hypervisor. The physical disk is provided by a computing device and stores at least a portion of a virtual disk. The hypervisor executes on the computing device. The hypervisor allocates, to the virtual disk, an amount of access to the physical disk. The hypervisor determines that a level of utilization of the physical disk has exceeded a threshold. The hypervisor limits, in response to the determination, access by the virtual disk to the physical disk.

Abstract: A system for optimizing a process of determining a location of data identified by a virtual hard drive address includes a virtual hard drive, a hypervisor, a plurality of chained files and a table. The plurality of chained files includes a first file comprising a delta of a master file and each subsequent file comprising a delta of a previous file in the plurality of chained files. The table enumerates associations between each of a plurality of virtual hard drive addresses with one of the master file and a file in the plurality of chained files. The virtual hard drive stores the master file, the plurality of chained files, and the table. The hypervisor intercepts a request to access data at a virtual hard drive address and identifies, based on the table, a file containing the requested data and responds to the request with access to the requested data.

Abstract: A system for controlling, by a hypervisor, access to physical resources during execution of a virtual machine includes a physical disk and a hypervisor. The physical disk is provided by a computing device and stores at least a portion of a virtual disk. The hypervisor executes on the computing device. The hypervisor allocates, to the virtual disk, an amount of access to the physical disk. The hypervisor determines that a level of utilization of the physical disk has exceeded a threshold. The hypervisor limits, in response to the determination, access by the virtual disk to the physical disk.

Abstract: A system for optimizing a process of determining a location of data identified by a virtual hard drive address includes a virtual hard drive, a hypervisor, a plurality of chained files and a table. The plurality of chained files includes a first file comprising a delta of a master file and each subsequent file comprising a delta of a previous file in the plurality of chained files. The table enumerates associations between each of a plurality of virtual hard drive addresses with one of the master file and a file in the plurality of chained files. The virtual hard drive stores the master file, the plurality of chained files, and the table. The hypervisor intercepts a request to access data at a virtual hard drive address and identifies, based on the table, a file containing the requested data and responds to the request with access to the requested data.