nStor NexStor 4200F Series, User Manual

Page: 34 / 174

Chapter 2 - Topologies and Operating Modes
Simplex Mode
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Simplex Mode
The simplex operating mode is a single RAID controller solution that provides a
limited level of redundancy. With its support for dual port topology, it further
provides dual active host ports on the controller which can be on separate or the
same Fibre loops.
In a simplex operting mode environment, failover is not a factor since there is
only one controller. It’s important to enable the controller’s “Force Simplex”
parameter. This releases the controller’s processor resources from constantly
checking for its partner controller.
The controller’s failover topology parameter provides for up to five different
failover topologies. We recommend setting your controller’s failover topology
parameter to Multi-Port for this operating mode.
The Multi-TID topology is designed for duplex operating modes where the
controller has the ability to function as multiple target ports on a single arbitrated
loop and allows the failed controllers’ port to be impersonated or be accessed on
the surviving controllers’ port. This failover topology is not applicable to simplex
operating mode.
NOTE: There are three other topologies included in the controller’s failover
topology parameters that are not supported: Inactive Port, Clustering
Failover, and Master-Slave.
The following topology configurations are available for the Simplex mode:
■
Dual Port Single Host Single Connection
■
Dual Port Single Host Dual Connection
■
Dual Port Multi Host Connection
4200F.book Page 22 Thursday, January 23, 2003 2:47 PM