Management of multiple software images with shared memory blocks

A computer implemented method for managing multiple software images on a data processing entity that includes a mass memory with a plurality of memory locations, each of the memory locations having a corresponding memory address within the mass memory, each of the software images including a plurality of memory blocks, each of the memory blocks having a corresponding image address within the software image, comprising:nstoring a single version of each memory block of at least a subset of all of the software images into a corresponding memory location;providing a control structure that associates each memory block with the memory location storing the single version of the memory block;relocating the memory blocks stored in boot locations of a current software image, the boot locations of each software image being the memory locations having the memory addresses equal to the image addresses of boot blocks of the software image including the memory blocks required to boot the data processing entity up to load an access function adapted to access the memory blocks of the software image;storing the boot blocks of the current software image into the corresponding boot locations;booting the data-processing entity from the boot blocks of the current software image in the corresponding boot locations thereby loading the access function; andserving, by the access function, each request to access a selected memory block of the current software image, the access function accessing the selected memory block in the associated memory location provided by the control structure.

A computer program product comprising:na computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising:computer readable program code configured for:managing multiple software images on a data processing entity that includes a mass memory with a plurality of memory locations, each of the memory locations having a corresponding memory address within the mass memory, each of the software images including a plurality of memory blocks, each of the memory blocks having a corresponding image address within the software image, wherein the managing includes:storing a single version of each memory block of at least a subset of all of the software images into a corresponding memory location,providing a control structure that associates each memory block with the memory location storing the single version of the memory block,relocating the memory blocks stored in boot locations of a current software image, the boot locations of each software image being the memory locations having the memory addresses equal to the image addresses of boot blocks of the software image including the memory blocks required to boot the data processing entity up to load an access function adapted to access the memory blocks of the software image,storing the boot blocks of the current software image into the corresponding boot locations,booting the data-processing entity from the boot blocks of the current software image in the corresponding boot locations thereby loading the access function, andserving, by the access function, each request to access a selected memory block of the current software image by the access function, the access function accessing the selected memory block in the associated memory location provided by the control structure.

A computer system comprising:na processor configured for:managing multiple software images on a data processing entity that includes a mass memory with a plurality of memory locations, each of the memory locations having a corresponding memory address within the mass memory, each of the software images including a plurality of memory blocks, each of the memory blocks having a corresponding image address within the software image, wherein the managing includes:storing a single version of each memory block of at least a subset of all of the software images into a corresponding memory location,providing a control structure that associates each memory block with the memory location storing the single version of the memory block,relocating the memory blocks stored in boot locations of a current software image, the boot locations of each software image being the memory locations having the memory addresses equal to the image addresses of boot blocks of the software image including the memory blocks required to boot the data processing entity up to load an access function adapted to access the memory blocks of the software image,storing the boot blocks of the current software image into the corresponding boot locations,booting the data-processing entity from the boot blocks of the current software image in the corresponding boot locations thereby loading the access function, andserving, by the access function, each request to accessing a selected memory block of the current software image, the access function accessing the selected memory block in the associated memory location provided by the control structure.