A logic arrangement, method and computer program for reducing incidence of
errors in a redundant path system during a process of attachment of a
device to a running subsystem, comprises a control component for
encapsulating the process of attachment of a device to a running
subsystem; a disabling component for disabling a path interface; a
testing component for testing for the presence of a usable data path
across at least one further path interface; and an enabling component for
enabling the at least one further path interface to accept communication
with the device responsive to a positive outcome from the testing
component; wherein the control component is adapted to permit operation
after attachment of the device only if full redundancy is retained. A
re-enabling component may re-enable any path interface or further path
interface.