Mti Technology Corporation

Don Sawdy

Arthur L Rogers

A method and apparatus for reducing the bring-up time upon a transfer of control. This is accomplished by performing the physical level access bring-up prior to fail-over or other transfer, on the devices which are only secondarily controlled by the controller. The media level access is performed only by the controller with primary control of the devices. Upon a failure or transfer by the first controller, a media level access can be immediately performed by the second controller without doing a physical level access first, since this had been done prior to the fail-over or transfer.

Controller fail-over without device bring-up

A method and apparatus for determining proper cabling and identical device locations between two controllers in a RAID system. Each controller first obtains the port names to which it is attached. The list is then reviewed to determine that there are no duplicate entries. Once this step is completed, the controllers exchange their port name lists. The lists are compared to make sure they exactly match. Finally, the controllers exchange a map of the devices themselves present on two channels. The exchange device maps are compared and must be equal. The two device maps being equal indicate that each storage device is logged on to the network through both I/O ports and is available to each controller.

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San Jose, CA, United States of America

Don Sawdy