Example: Counting devices

This example shows how the number of devices on a fabric is calculated.

For this example, the configuration for the subnet is shown in the following table.

Table 1. Example configuration
Quantity	Devices	Connectivity
1	9024 switch	5 HCA connections + 4 connections to the 9120
1	9120 switch	5 HCA connections + 4 connections to the 9024
3	9125-F2A	(1) IBM® GX HCAs per node
3	IBM GX host channel adapters (HCAs)	1 connection to 9024; 1 connection to 9120
2	InfiniBand Management Hosts	(1) 2-port PCI HCA per host
2	PCI HCAs	1 connection to 9024; 1 connection to 9120

The resulting report from the master subnet manager is shown in the following table.

DETAIL:25 SWs, 5 HCAs, 10 end ports, 353 total ports, 4 SM(s)

Table 2. Report from the master subnet manager
Resource	Count	Calculation
Switches	25	(1) per 9024 # 12 leaf chips per 9120 + # 2 chips * 3 spines per 9120 + # 2 logical switch per HCAs * 3 GX HCAs = 1 + 12 + 6 + 6 = 25
HCAs	5	(2) PCI HCAs + (3) IBM GX HCAs
End ports	10	5 HCAs * 2
Ports	353	See the example ports calculation that follow
Subnet managers	4	(1) Master + (3) Standbys

The following table illustrates how the number of ports were calculated.

Table 3. Number of ports calculation
Device	Ports	Calculation
9024	10	(3) connections to GX HCAs + (2) connections to PCI HCAs + (4) switch to switch connections + (1) management port
9120 spines	150	25 ports * 3 spines * 2 switch chips per spine
9120 leaf chips	165	(13 ports * 12 leaf chips) + (3) connections to GX HCAs + (2) connections to PCI HCAs + (4) switch to switch connections
Logical switches	18	3 ports * 6 logical switches
Logical HCAs	6	2 ports * 3 logical HCAs
PCI HCAs	4	2 ports * 2 HCAs

Total Port Count = 10 + 150+165+18+6+4 = 353