Device Fan-Out Ratio - McDATA StorageWorks 2/140 - Director Switch Planning Manual

Figure 3-14
Performance Tuning
Device Fan-Out Ratio: 10 to 1
10,000 IOPS
Interswitch Link
Fabric Connection

Device Fan-Out Ratio

When designing or tuning a fabric for performance, it is critical to
understand application I/O characteristics so that:
• Device output in Gbps does not oversubscribe ISLs, leading to
fabric congestion.
• Device output in IOPS does not result in a connectivity scheme
that exceeds fan-out ratios, leading to port congestion.
Figure 3-15 illustrates performance tuning for a simple fabric using
appropriate ISL connectivity, device locality, and fan-out regions for
device connectivity. The fabric is comprised of one core director and
six edge switches. Tier 2 servers connect to three switches at the
bottom of the figure, and Tier 2 storage devices connect to three
switches at the top of the figure.
Planning Considerations for Fibre Channel Topologies
Planning Considerations for Fibre Channel Topologies
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
1,000 IOPS
3
3-35