IBM BladeCenter T 8720 Installation And User Manual page 23

servers or power, management, I/O, KVM, LAN or blower modules in hot-swap
bays within specified time limits and without removing power from the
BladeCenter T unit. See Chapter 3, "Removing and installing BladeCenter T
modules and options," on page 25 for detailed instructions.
Attention: To maintain proper system cooling, each unoccupied bay must
contain a filler blade or filler module.
v Redundancy capabilities
The following redundant components in the BladeCenter T unit enable continued
operation if one of the components fails:
– Power modules: In normal operation, the redundant power modules provide
redundant power feeds to share the system load. If one of the power modules
fails, the working power module handles the entire load. You can then replace
the failed power module without shutting down the BladeCenter T unit.
– Blowers: In normal operation, the redundant blower modules share the system
load. If one of the blowers fails, the other three working blowers handle the
entire load. You can then replace the failed blower without shutting down the
BladeCenter T unit.
– Management modules: Only one management module is active at a time. If a
second management module has been installed and the active management
module fails, the secondary (redundant) management module becomes the
active management module containing the current BladeCenter T
configuration and status information. You can then replace the failed
management module without shutting down the BladeCenter T unit.
– BladeCenter T backplane characteristics: The backplane has the following
redundancy characteristics:
- Hot-pluggable connectors for the following components:
v Eight blade servers
v Four I/O modules
v Two management modules
v Four power supplies
v Four blowers
- Redundant high-speed SERDES interconnects between blade servers and
switches
- Support for redundant management modules
v Redundant I2C communications between management modules and all
modules (except the blade servers)
v Redundant RS-485 communications between management modules and
blade servers
v Redundant analog video connections from blade servers to management
modules
v Redundant USB connections between blade servers and management
modules
v Redundant, secure Ethernet management port between switches and
management modules
v Redundant network connection capabilities
Configuring a pair of Ethernet switch modules in I/O-module bays 1 and 2
provides support for Ethernet failover configured on blade servers. See
"Configuring an I/O module" on page 68 for more information. If the I/O
expansion options in your blade servers can be configured for failover,
9
Chapter 1. Introduction