Symmetrix Consolidation Application; Symmetrix Spider Graphic - EMC Connectrix EC-1200 Planning Manual

Symmetrix
Consolidation
Application
Figure 4-3
Many server environments contain servers that demand low to
moderate storage capacity. Storage resource managment is best done
when multiple servers consolidate their storage demands on a few
high-capacity Symmetrix systems. The fan-out logical topology
provides a solution to the Symmetrix consolidation application.
The concept of fan-out is derived from the widely used Symmetrix
spider graphic (Figure 4-3), where a small number of Symmetrix ports
expand outward to a large number of server ports.
Hosts Hubs Switches

Symmetrix Spider Graphic

In a recent survey of four topologies (fan-out, fan-in, tape backbone,
and SRDF™), fan-out was used in more cases than the other three
topologies combined. The same survey indicated that 85% of the
installations were using a ratio of four or more server ports for every
Symmetrix port. (This is referred to as a fan-out rate.) As the capacity
of individual disk drives increases and the power of storage resource
management software strengthens, fan-out rates will continue to
increase.
The set of switch ports, the switch ports that connect to the servers,
and the switch port that connects to the Symmetrix, make up a fan-out
group. The concept of a fan-out group is used when considering the
ISL-loading issues in the design of a mutiswitch fabric.
Switches Hubs
Symmetrix
Base Switch Topologies
Connectrix Topologies
Hosts
4-5
4