Combined Topologies; Calculating Fan-In And Fan-Out; Combined Topologies Example - EMC Connectrix EC-1200 Planning Manual

Combined
Topologies
Figure 4-5
Calculating Fan-in
and Fan-out
Figure 4-5 shows how topologies can be combined for maximum
efficiency, achieving large Symmetrix storage capacity for many
servers while minimizing the necessary number of HBAs and
Symmetrix FA ports.
Server 1
Server 2
Server 3
Server 4

Combined Topologies Example

This type of configuration can take advantage of PowerPath and the
redundancy of dual switches to provide alternative routes if
necessary.
Switch port assignment does not affect performance. There are no
internal resources in the switch that create port-to-port performance
interactions. As a result, sharing Fibre Channel ports on the same
port card or between port cards is not a performance consideration. It
is, however, an important availability consideration.
Symmetrix port assignment, on the other hand, does affect
performance. The consolidation application combines the workload
of HBAs from multiple servers onto a single Symmetrix port.
Therefore, the sum of the server I/O workloads (taking into account
peak loads, batch loads, and backup loads) is an important
determinant of the sharing assignment and the fan-out rate.
You can calculate the fan-out ratio by estimating the total I/Os per
second (IOPS) on the servers to be connected to Symmetrix Fibre
Channel director port. Then, utilizing the I/O rates chart in Figure 4-6
and a utilization factor or response time factor from the response time
chart in Figure 4-7, calculate the number of hosts that can
Connectrix
Symmetrix 1, FA-1A
Symmetrix 2, FA-1A
Symmetrix 3, FA-1A
Symmetrix 4, FA-1A
Base Switch Topologies
Connectrix Topologies
4-7
4