PREVENTION AND RESOLUTION OF A CRITICAL SHORTAGE OF A SHARED RESOURCE IN A MULTI-IMAGE OPERATING SYSTEM ENVIRONMENT

A technique relates to resource allocation of a countable managed resource. A computer sets a reserved amount of the managed resource to be available for a privileged status, such that there is an unreserved amount of the managed resource to be available for a non-privileged status. In response to a non-privileged job needing more of the unreserved amount of the managed resource than what is available, it is determined whether the non-privileged job is promotable to the privileged status. In response to the non-privileged job not being promotable to the privileged status, the non-privileged job is prevented from accessing the reserved amount of the managed resource. In response to the non-privileged job being promotable to the privileged status, the non-privileged job is permitted to utilize the reserved amount of the managed resource.