nStor 4100FS, Руководство пользователя

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Chapter 4
SAN Solution Strategies
This chapter will describe connecting the NexStor 4120FS Series Storage Systems
providing an Active-Active/Active-Passive solution to a Storage Area Network
(SAN).
Active-Active:Dual Port Mode for SAN
At the heart of this strategy is the Active-Active Dual Port operating mode. In this
mode, four Fibre Channel (FC) ports are simultaneously active when both
controllers are online. In the event of a controller failure, two FC ports remain
available to service all host I/O. The table below illustrates how LUNs are
presented by each controller in this mode.
Note that when a controller fails, the surviving controller continues to present its
LUNs to its Host Port 0, and changes to present the failed controller’s LUNs to its
Host Port 1. The Fibre Channel Node and Port World Wide Names corresponding
to the failed controller’s Host Port 0 (FC1) are also associated with its LUNs on
the surviving controller’s Host Port 1 (FC2).
Controller 1
Host Port 0 (FC1)
Controller 1
Host Port 1 (FC2)
Controller 2
Host Port 0 (FC1)
Controller 2
Host Port 1 (FC2)
Both Controllers Online Controller 1
LUNs
Controller 1
LUNs
Controller 2
LUNs
Controller 2
LUNs
Controller 1 Failed Inactive Inactive Controller 2
LUNs
Controller 1
LUNs
Controller 2 Failed Controller 1
LUNs
Controller 2
LUNs
Inactive Inactive
4100FS.book Page 71 Tuesday, July 8, 2003 4:35 PM