FW V06.XX/HAFM SW V08.02.00 HP StorageWorks SAN High Availability Planning Guide (AA-RS2DD-TE, July 2004)

Planning Considerations for Fibre Channel Topologies
104 SAN High Availability Planning Guide
Performance Tuning
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 44 illustrates performance tuning for a simple fabric using appropriate ISL
connectivity, device locality, and fan-out regions for device connectivity.
Figure 44: Fabric performance tuning
Interswitch Link
Fabric Connection
6,000 IOPS
Tier 2 Storage
P
W
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M
30 Mbps
2,000 IOPS
20 MBps
1,500 IOPS
10 MBps
1,000 IOPS
11 to 1 Fan-Out Region
11,000 IOPS
11 Total
Servers
6 Total
Servers
3 Total
Servers
Local Tier 1 Devices
40 Mbps
2,000 IOPS
2,000 IOPS
T
M
6 to 1 Fan-Out Region
9,000 IOPS
3 to 1 Fan-Out Region
6,000 IOPS
Tier 2 Servers