Some computers also allow hotplug for PCI devices. To make full use of this, it is necessary for special kernel modules to be loaded. However, on non-PCI hotplug computers, these modules could cause problems. Unfortunately, hotplug PCI slots cannot be automatically detected, so you have to configure this function manually. To do this, set variable HOTPLUG_DO_REAL_PCI_HOTPLUG in file /etc/sysconfig/hotplug.