topological structure of FC-AL is network, topological structure of of FC-SW is circular

FC-AL use AL-PA query equipment, FC-SW use Name Server query equipment

when there is new equipment join in, FC-AL need to interrupt network, FC-SW don't need to

interrupt the network

FC-AL through the hub as connection device, FC-SW optical switches as connected devices

when create LUN copy , you can use one virtual snapshot of LUN as the source of LUN

when create increment LUN copy, you can use external array as the source of LUN

when create full capacity of LUN copy, the source of LUN and target of LUN can't be located in

the external array at the same time

multiple LUN copy can share same target of LUN

FC-0 is the physical layer to complete data transceiver

FC-1 is responsible for encoding and decoding

FC-2 is the public service

FC-4 is the application layer