Abstract: A mechanism is provided for making information about the virtual disk image file and/or its associated virtual image configuration file more readily available to a user. The virtual disk image file format is expanded to include fields in which information about the data in the file can be stored. Extensible information on file content, compatible HW configurations, compatible host OSes, timeout status, DRM status, patch state, and network topology, tag data for indexing, configuration files, saved state files, operation history data, and the like is stored in a location within a virtual disk image file that can be read without executing the virtual machine. This information can then be used to search the contents of the virtual disk image, to enforce usage policies, to provide extensibility for vendors, and the like.

Abstract: A system is described for high-performance delivery of applications via attachable application storage volumes (ASV), particularly in cloud-based VDI environments, by precaching application data that is determined by learning the application behavior. Data blocks for files that are likely to be used by the application are prefetched and cached by virtual machines before the application requests those blocks so that the relevant data is instantly available in memory when required without needing to wait for the data to be transmitted from the ASV. In order to efficiently prefetch content, the read pattern for application files and their corresponding blocks is inspected. This information is used during application delivery after a user logs onto the virtual machine to selectively prefetch those blocks from the ASVs. As a result, when the user launches those applications, the system avoids the performance penalty of reading those blocks from the ASV.