Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: In various embodiments, methods and systems for providing access to file systems are provided. An SFA-based operation having an operation modifier for a file in a file system is received. The SFA-based operation is defined based on a file-representational state transfer (REST) interface. The SFA-REST interface comprises integrated functionality of an SFA protocol and REST protocol. The SFA-based operation is executed using the operation modifier. A REST-based operation for the file in the distributed file storage is received. The REST-based operation is defined based on the SFA-REST interface. The operation modifier is referenced in order to execute the REST-based operation. The REST-based operation based on the SFA-REST interface. A schema can be implemented for accessing the file system. The schema includes tables to store files, the table comprises fields corresponding to elements of a SFA-REST interface. A snapshot component can be implemented to backup file shares in the file system.

Abstract: A data storage system includes multiple head nodes and data storage sleds. A control plane of the data storage system designates, for a volume partition, one of the head nodes to function as a primary head node storing a primary replica of the volume partition and designates two or more other head nodes to function as reserve head nodes storing reserve replicas of the volume partition. Additionally, the primary head node causes volume data for the volume partition to be erasure encoded and stored on multiple mass storage devices in different ones of the data storage sleds.

Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: Generally described, one or more aspects of the present application relate to a public snapshot service for creating and managing block-level snapshots. Snapshots can be configured to enable writing at the sub-block level. Subsequent modifications made to blocks storage volume that forms the basis of the snapshots can be backed up as a sub-block level operations.

Abstract: Generally described, one or more aspects of the present application relate to a public snapshot service for creating and managing block-level snapshots. Snapshots can be configured to enable writing at the sub-block level. Subsequent modifications made to blocks storage volume that forms the basis of the snapshots can be backed up as a sub-block level operations.

Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: In various embodiments, methods and systems for providing access to file systems are provided. An SFA-based operation having an operation modifier for a file in a file system is received. The SFA-based operation is defined based on a file-representational state transfer (REST) interface. The SFA-REST interface comprises integrated functionality of an SFA protocol and REST protocol. The SFA-based operation is executed using the operation modifier. A REST-based operation for the file in the distributed file storage is received. The REST-based operation is defined based on the SFA-REST interface. The operation modifier is referenced in order to execute the REST-based operation. The REST-based operation based on the SFA-REST interface. A schema can be implemented for accessing the file system. The schema includes tables to store files, the table comprises fields corresponding to elements of a SFA-REST interface. A snapshot component can be implemented to backup file shares in the file system.

Abstract: In various embodiments, methods and systems for providing access to file systems are provided. An SFA-based operation having an operation modifier for a file in a file system is received. The SFA-based operation is defined based on a file-representational state transfer (REST) interface. The SFA-REST interface comprises integrated functionality of an SFA protocol and REST protocol. The SFA-based operation is executed using the operation modifier. A REST-based operation for the file in the distributed file storage is received. The REST-based operation is defined based on the SFA-REST interface. The operation modifier is referenced in order to execute the REST-based operation. The REST-based operation based on the SFA-REST interface. A schema can be implemented for accessing the file system. The schema includes tables to store files, the table comprises fields corresponding to elements of a SFA-REST interface. A snapshot component can be implemented to backup file shares in the file system.

Abstract: Techniques are disclosed for coalescing timer ticks generated by timers used to service guest operating systems executing in virtual machines. By coalescing timer ticks a logical processor can enter a low power mode thereby reducing power consumed by the system.

Abstract: A data storage system includes multiple head nodes and data storage sleds. A control plane of the data storage system designates, for a volume partition, one of the head nodes to function as a primary head node storing a primary replica of the volume partition and designates two or more other head nodes to function as reserve head nodes storing reserve replicas of the volume partition. Additionally, the primary head node causes volume data for the volume partition to be erasure encoded and stored on multiple mass storage devices in different ones of the data storage sleds.

Abstract: A DMA-capable device of a virtualization host stores a DMA write record, indicating a portion of host memory that is targeted by a DMA write operation, in a write buffer accessible from a virtualization management component of the host. The virtualization management component uses the DMA write record to identify a portion of memory to be copied to a target location to save a representation of a state of a particular virtual machine instantiated at the host.

Abstract: One or more virtual processors can be added or removed from a virtual machine based on CPU pressure measured within the virtual machine. In addition to the foregoing, CPU pressure can also be used to determine whether to remove a virtual processor from a virtual machine, which may cause the computer system to consume less power. In the alternative, virtual processors can be parked and/or unparked in order to reduce the amount of power consumed by the virtual machine. In addition, virtual processors can be forcibly parked during a migration operation.

Abstract: A computing system in which a software component executing on a platform can reliably and efficiently obtain state information about a component supported by the platform through the use of a shared memory page. State information may be supplied by the platform, but any state translation information needed to map the state information as supplied to a format as used may be provided through the shared page. In a virtualized environment, the state translation information can be used to map the value of a virtual timer counter or other component from a value provided by a virtual processor to a normalized reference time that will yield the same result, regardless of whether the software component is migrated to or from another virtual processor. Use of a shared page avoids the inefficiency of an intercept into a virtualized environment or a system calls in native mode operation.

Abstract: Described is a technology by which a virtual machine may be safely migrated to a computer system with a different platform. Compatibility of the virtual machine may be checked by comparing the virtual machine's capabilities against those of the new platform. To ensure compatibility, when created the virtual machine may have its capabilities limited by the lowest common capabilities of the different platforms available for migration. Computer systems may be grouped into migration pools based upon similar capabilities, and/or a virtual machine may be mapped to certain computer systems based upon capabilities needed by that virtual machine, such as corresponding to needed performance, fault tolerance and/or flexibility.

Abstract: Principles for enabling power management techniques for virtual machines. In a virtual machine environment, a physical computer system may maintain management facilities to direct and control one or more virtual machines executing thereon. In some techniques described herein, the management facilities may be adapted to place a virtual processor in an idle state in response to commands from a guest operating system. One or more signaling mechanisms may be supported such that the guest operating system will command the management facilities to place virtual processors in the idle state.

Abstract: Described is a technology by which a virtual machine may be safely migrated to a computer system with a different platform. Compatibility of the virtual machine may be checked by comparing the virtual machine's capabilities against those of the new platform. To ensure compatibility, when created the virtual machine may have its capabilities limited by the lowest common capabilities of the different platforms available for migration. Computer systems may be grouped into migration pools based upon similar capabilities, and/or a virtual machine may be mapped to certain computer systems based upon capabilities needed by that virtual machine, such as corresponding to needed performance, fault tolerance and/or flexibility.

Abstract: Described is a technology by which a virtual machine may be safely migrated to a computer system with a different platform. Compatibility of the virtual machine may be checked by comparing the virtual machine's capabilities against those of the new platform. To ensure compatibility, when created the virtual machine may have its capabilities limited by the lowest common capabilities of the different platforms available for migration. Computer systems may be grouped into migration pools based upon similar capabilities, and/or a virtual machine may be mapped to certain computer systems based upon capabilities needed by that virtual machine, such as corresponding to needed performance, fault tolerance and/or flexibility.

Abstract: Principles for enabling power management techniques for virtual machines. In a virtual machine environment, a physical computer system may maintain management facilities to direct and control one or more virtual machines executing thereon. In some techniques described herein, the management facilities may be adapted to place a virtual processor in an idle state in response to commands from a guest operating system. One or more signaling mechanisms may be supported such that the guest operating system will command the management facilities to place virtual processors in the idle state.