Flexible temporary capacity upgrade/downgrade in a computer system without involvement of the operating system

A device for concurrent removal of processor capacity from a running computer having a and,, the device comprising:

• a resource controller configured to control a physical resource pool including the actual physical resources;
• and
• a capacity virtualizer being configured to provide multiple sets of virtual resources from a capacity virtualizer resource, whereby said provided sets of virtual resources allow hosting of independent operating systems concurrently;
• said resource controller requesting said capacity virtualizer to reduce said capacity virtualizer resource pool,
• said capacity virtualizer removing resources from said capacity virtualizer resource pool, and
• said resource controller disabling physical resources corresponding to the resources removed from said capacity virtualizer resource pool.

A computer program product for concurrent removal of processor capacity from a running computer having a resource controller being configured to control a physical resource pool including the actual physical resources, and a capacity virtualizer being configured to provide multiple sets of virtual resources from a capacity virtualizer resource pool, whereby said provided sets of virtual resources allow hosting of independent operating systems concurrently, said program product comprising:

• a computer usable medium;
• a computer readable program stored on said computer usable medium for causing a computer to perform a method comprising the steps of:
• requesting said capacity virtualizer to reduce said capacity virtualizer resource pool;
• removing resources from said capacity virtualizer resource pool;
• and
• disabling physical resources corresponding to the resources removed from said capacity virtualizer resource pool.