Upgrade of software images based on streaming technique

摘要

Migrating a data-processing entity from a source software image installed on a mass memory of the data-processing entity to a target software image stored on an external source. A portion of mass memory is released. Memory blocks stored in boot locations of the target software image are relocated to the released portion, including memory blocks required to boot the data-processing entity to load a streaming function for downloading the target software image from the external source. The data-processing entity is booted from the boot blocks, thereby loading the streaming function. Each request for reading a selected memory block of the target software image is served by the streaming function, which downloads the selected memory block from the external source and stores it into the released portion when the selected memory block is not available in the mass memory, or retrieves the selected memory block from the mass memory.

主权项

1. A method for migrating a data-processing entity from a source software image installed on a mass memory of the data-processing entity to a target software image stored on an external source, each software image including a plurality of memory blocks, each memory block having a corresponding image address within the software image, and the mass memory including a plurality of memory locations for storing memory blocks, each memory location having a corresponding memory address within the mass memory, wherein the method includes the steps of:
releasing a portion of the mass memory; relocating memory blocks stored in boot locations of the target software image to the released portion, the boot locations being memory locations having memory addresses equal to the image addresses of boot blocks of the target software image including memory blocks required to boot the data-processing entity to load a streaming function adapted to download the target software image from the external source; storing the boot blocks into the corresponding boot locations, booting the data-processing entity from the boot blocks in the corresponding boot locations thereby loading the streaming function; and serving each request for reading a selected memory block of the target software image by the streaming function, the streaming function downloading the selected memory block from the external source and storing the selected memory block into the released portion when the selected memory block is not available in the mass memory, or retrieving the selected memory block from the mass memory otherwise.