Use of cloning in maintenance of virtual appliances

Computer-readable hardware with an executable program for maintaining a current virtual appliance comprising a set of software components each one installed on a corresponding virtual machine stored thereon, wherein the program instructs a processor to perform:

• retrieving a maintenance descriptor comprising an indication of a new level of at least one of the software components to be updated;
• determining, for each software component indicated in the maintenance descriptor, a current level of the software component being installed on the corresponding virtual machine;
• determining a set of old ones of the software components to be actually updated according to a comparison between the corresponding current levels and new levels;
• determining local data of the current virtual appliance,
• cloning the current virtual appliance in response to determining that software components need to be updated;
• updating the cloned virtual appliance by updating each old software component thereof to the new level, wherein the updating occurs while the current virtual appliance is running;
• determining changes to the local data of the current virtual appliance that occurred to the current virtual appliance during the updating of the cloned virtual appliance;
• applying the changes to the local data of the current virtual appliance to the updated cloned virtual appliance;
• and
• replacing the current virtual appliance with the updated cloned virtual appliance.

A system comprising:

• a processor coupled to a memory;
• wherein the processor is programmed to maintain a current virtual appliance comprising a set of software components each one installed on a corresponding virtual machine by:
• retrieving a maintenance descriptor comprising an indication of a new level of at least one of the software components to be updated;
• determining, for each software component indicated in the maintenance descriptor, a current level of the software component being installed on the corresponding virtual machine;
• determining a set of old ones of the software components to be actually updated according to a comparison between the corresponding current levels and new levels;
• determining local data of the current virtual appliance,
• cloning the current virtual appliance in response to determining that software components need to be updated;
• updating the cloned virtual appliance by updating each old software component thereof to the new level, wherein the updating occurs while the current virtual appliance is running;
• determining changes to the local data of the current virtual appliance that occurred to the current virtual appliance during the updating of the cloned virtual appliance;
• applying the changes to the local data of the current virtual appliance to the updated cloned virtual appliance;
• and
• replacing the current virtual appliance with the updated cloned virtual appliance.