Methods and subsystems that efficiently distribute VM images in distributed computing systems

A method carried out in a distributed VM-image-distribution subsystem of a management system within a distributed computer system having multiple servers, multiple data-storage devices, and one or more internal networks, the method comprising:

• organizing data stores within the distributed computer system that store VM images into groups, each group including an image data store and multiple associated local data stores;
• classifying each VM image as one of an EAGER image and an ON_DEMAND image;
• when an EAGER image is created and stored in a first image data store, propagating the VM image to the remaining image data stores within the distributed computer system and propagating the VM image from each image data store to the local data stores associated with the image data store;
• when an ON_DEMAND image is created and stored in a first image data store, propagating the VM image to the remaining image data stores within the distributed computer system;
• and
• when the management system processes a request to instantiate an ON_DEMAND image on a server, transferring the ON_DEMAND image from an image data store to a local data store accessible to the server.

Computer instructions stored on a physical data-storage device that, when executed by one or more processors in a distributed computer system having multiple servers, multiple data-storage devices, and one or more internal networks, control a distributed VM-image-distribution subsystem of a management system within the distributed computer system to:

• organize data stores within the distributed computer system that store VM images into groups, each group including an image data store and multiple associated local data stores;
• classify each VM image as one of an EAGER image and an ON_DEMAND image;
• when an EAGER image is created and stored in a first image data store, propagate the VM image to the remaining image data stores within the distributed computer system and propagate the VM image from each image data store to the local data stores associated with the image data store;
• when an ON_DEMAND image is created and stored in a first image data store, propagate the VM image to the remaining image data stores within the distributed computer system;
• and
• when the management system processes a request to instantiate an ON_DEMAND image on a server, transfers the ON_DEMAND image from an image data store to a local data store accessible to the server.