After modification of the driver it is possible to RELOAD it without rebooting the system, provided that the size of the UCB did not change. If the reloaded driver detects a different UCB size, the unit will be placed off-line and the system has to be rebooted. The reload is only possible on a VAX. If there is still a file or device connected to any LDAn device the driver cannot be reloaded. In that case all LDAn devices have to be disconnected first. If a tracebuffer is allocated before reloading, it will be deallocated. All trace data will be lost.