Specifications

DATA CENTER BEST PRACTICES
SAN Design and Best Practices 19 of 84
fig15_SAN_Design
4 × 8 Gbps Control Ports
4 × 8 Gbps ISLs
1:1 Oversubscription for Initiator to the Core
Figure 15. One-to-one oversubscription for targets into the core.
The realized oversubscription ratio of host-to-ISL should be roughly the same as the host-to-target ratio, taking
into account the bandwidth (that is, if there are four hosts accessing a single 4 Gbps storage port, then those
four hosts should have a 4 Gbps pipe into the core.) In other words, match device utilization and speeds with
ISL speeds, as shown in Figure 16.
fig16_SAN_Design
24 x 4 Gbps Initiators
4 × 8 Gbps ISLs
3:1 Oversubscription for Initiator to the Core
Figure 16. Three-to-one oversubscription for hosts coming into the core.