NEC VERSA S1300 Series, User Manual

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Initial Assignment Feature
You can assign a logical disk (LD) to the controller on the path to which you bound that
logical disk (built the RAID).
When an attempt is made to access the logical disk from the unassigned controller, the
error 05/04/00 ("illegal request - not assigned") is returned. When an attempt is made
to unbind this logical disk from the unassigned controller, the same error is returned.
However, if the ownership has been changed, the initial assignment feature is
transferred to the unassigned controller.
Auto Assignment Feature
This feature is active while the cross call is being disabled. The auto assignment
feature allows you to access any logical disk in the subsystem from the unassigned
controller if the assigned controller gets down.
When an I/O is received on a logical disk not assigned to the local controller, the system
examines whether the adjacent controller is in down state. If the adjacent controller is in
down state, the system reassigns the logical disk to the local controller. This
reassignment is maintained until the power is turned on again or the status is changed
using the management software.
Even when the system is not equipped with the alternative path switching feature,
making the system recognize the logical disk again permits the access, allowing to
minimize the influence to the system operation.
Figure 1-12 Auto Assignment Feature
System Overview 1-23