Microsoft Technology Licensing, LLC

Chung Lang Dai

Dustin Lyle Green

Neal Robert Christiansen

John Andrew Starks

Karan Mehra

Senthil Rajaram

Mathew John

Todd William Harris

Vladimir Stoyanov

Joy Chik

Alan M Warwick

Ahmed Tolba

Narasimham Ramasubramanian

Mukund Sankaranarayan

Stuart Raymond Patrick

This document describes techniques for storing virtual disk payload data. In an exemplary configuration, each virtual disk extent can be associated with state information that indicates whether the virtual disk extent is described by a virtual disk file. Under certain conditions the space used to describe a virtual disk extent can be reclaimed and state information can be used to determine how read and/or write operations directed to the virtual disk extent are handled. In addition to the foregoing, other techniques are described in the claims, figures, and detailed description of this document.

Virtual disk storage techniques

The present disclosure provides systems and method for redirecting control of a client side connected USB device from the client to the server in a remote system. Specifically, the present disclosure creates a simulated USB device at the server. The simulated USB device is treated as a proxy for a redirected USB device at the client. The client side redirected USB device is not treated as the USB device but, rather, acts as a pass through to facilitate communication between requesting applications and the client connected device. The simulated USB device allows an application to send requests for a local device to the simulated USB device at the server. The simulated USB device then processes the requests and forwards the requests to the local device connected to the client.

USB device redirection for remote systems

Device redirection for remote systems

An invention is disclosed for maintaining out-of-band metadata for data. In embodiments of the invention, an upper layer of a storage stack determines that the metadata of a lower layer of that storage stack may have become out of sync. In response, the upper layer may issue a series of commands to the lower layer based on the metadata. In other embodiments of the invention, an offload-copy operation on data may also transfer out-of-band metadata so that it is applied to the data at the destination.

Re-TRIM of free space within VHDX

A centralized service identifies a pool of devices that can be accessed by clients over a network. Devices can include a local or network-accessible device, and a configurable file that represents a portion of a device (e.g., a SCSI storage device). In some cases, the devices (or the file representing a portion of the device) can be identified by an assigned logical unit number. The centralized service assigns one or more devices to a target, and associates client information with the target. The centralized service also can also assign the target a logical unit number, and assign the target to a protocol-independent portal, which further operates through protocol-dependent miniports. In one embodiment, a client accesses a network device by accessing the appropriate port through an appropriate miniport protocol (e.g., Ethernet, fiber channel, etc.), and by submitting appropriate target authorization.

Providing client access to devices over a network

A user-mode device driver architecture is provided by the subject invention. The architecture includes a reflector, a driver manager and a host process which hosts and isolates one or more user-mode device driver(s). The user-mode device driver runs in the user-mode (UM) environment and has access to various UM services. The reflector resides in 'kernel memory' (e.g., memory/resource(s) available to operating system) while the driver manager, host process and user mode device driver(s) are located in user space (e.g., memory/resource(s) available to user application(s)). The reflector provides a secure, stable communication path for application(s), the host process and/or user-mode device driver(s) to communicate with the operating system.

Protocol for communication with a user-mode device driver

Mechanisms that allow a physical storage device that has storage capability (such as a hard disk, tape drive, tape changer, or read-write compact disk) to emulate one or more storage devices. A configuration interface receives configuration function calls that specify properties of the storage device to be emulated. A front end component receives network communications and extracts SCSI commands from the network communication. An emulation software component establishes a file within the physical storage device in response to the configuration function call, determines that the SCSI command is intended for the emulated storage device, and uses the properties and the file storage space that correspond to the emulated storage device to fulfill the SCSI command in a manner that emulates the fulfillment of the SCSI command on the emulated storage device.

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Redmond, WA, United States of America

Chung Lang Dai