5
Cisco SFS 7012 InfiniBand Server Switch Hardware Users Guide
OL-8787-04
Chapter
Subnet Manager
Every InfiniBand fabric subnet requires a single active Subnet Manager (SM) to initialize and maintain
the subnet. The fabric may also have one or more standby Subnet Managers. One of the standby Subnet
Managers can be configured to become the active SM in the event of a failure.
As Figure 1-2 shows, InfiniBand-enabled fabrics consist of one or more subnets. Each subnet consists
of a number of InfiniBand-capable servers connected to target devices. InfiniBand-capable routers
provide connectivity between InfiniBand subnets.
Figure 1-2 Subnet Manager
When a network is initially powered up, the Subnet Manager queries the subnet management agents
running on the network devices, for information about node/port addressing schemes, routing tables and
partitions. From that point on, the Subnet Manager periodically sweeps the network for changes. Once
the InfiniBand network is up and running, the InfiniBand General Services Managers (GSMs) begin to
interface with General Services Agents (GSAs).
Subnet Management
Subnet Management Agents
A Subnet Management Agent processes management requests from the Subnet Manager. Subnet
Management Agents are implemented on all nodes within the InfiniBand fabric. These nodes include
IB-capable switches, routers, and channel adapters. Each node implements a Subnet Management Agent.
Within the SFS 7012 Switch, a Subnet Management Agent (SMA) is implemented within its firmware.
Subnet A
InfiniBand
Subnet Manager
for Subnet B
InfiniBand
Subnet Manager
for Subnet A
Subnet B
Router
InfiniBand
Capable Server
HCA
Router
InfiniBand
Capable Server
HCA
IB Port
IB Port
SFS 7012
IB Port
IB Port
IB Port
IB Port
IB Port
IB Port
