A resource and partition manager of the preferred embodiments includes a lock mechanism that operates on a plurality of locks that control access to individual PCI adaptor slots. The resource and partition manager uses the lock mechanism to obtain a lock on an PCI adaptor slot when transferring control of the PCI adaptor slot to a logical partition that is powering on and when removing the PCI adaptor from a logical partition that is powering off. The resource and partition manager uses the lock mechanism to remove control of an PCI adaptor slot from, or return control to, an operating logical partition in order to facilitate hardware service operations on that PCI adaptor slot or on the physical enclosure in which it is contained.