Virtual disks constructed from unused distributed storage

摘要

A virtual disk is comprised of segments of unused capacity of physical computer-readable storage media co-located with computing devices that are communicationally coupled to one another through network communications. The computing devices execute one or more of a client process, a storage process and a controller process. The controller processes manage the metadata of the virtual disk, including a virtual disk topology that defines the relationships between certain ones of the physical computer-readable storage media and a particular virtual disk. The client process provide data for storage to certain ones of the computing devices executing the storage processes, as defined by a virtual disk topology, and also read data from storage from those computing devices. The client process additionally expose the virtual disk in the same manner as any other computer-readable medium.

主权项

1. One or more computer-readable storage media comprising computer-executable instructions for implementing a virtual disk, the computer-executable instructions performing steps comprising:
receiving a virtual disk topology comprising a specification of: a top layer of child disks supporting the virtual disk, a bottom layer of child disks supporting each of the child disks in the top layer of child disks, and storage nodes supporting each of the child disks in the bottom layer of child disks such that data stored on each of the child disks in the bottom layer of child disks is actually stored in a storage segment that is stored on a computer-readable storage medium that is communicationally coupled to a computing device that is part of the storage nodes; presenting the virtual disk to an operating system as a standard computer-readable storage medium; receiving a first request from the operating system to store a first set of data on the virtual disk; storing, in response to the receiving the first request, the first set of data at least some of the storage nodes in accordance with the received virtual disk topology; receiving a second request from the operating system to read a second set of data from the virtual disk; reading, in response to the receiving the second request, the second set of data from at least some of the storage nodes in accordance with the received virtual disk topology.