Introduction

The Lenovo Flex System Enterprise Chassis Types 7893, 8721, and 8724 is a 10U next-generation server platform with integrated chassis management. It is a compact, high-density, high-performance, rack-mounted, scalable server platform system.

The Flex System Enterprise Chassis has fourteen node bays that support up to fourteen 1-bay compute nodes or up to seven 2-bay compute nodes when the shelves are removed from the chassis. You can use both 1-bay and 2-bay compute nodes to meet your specific hardware needs.

The Flex System Enterprise Chassis also supports 4-bay storage nodes, when the shelves and shelf supports are removed from the chassis. The Flex System Enterprise Chassis can support up to three 4-bay storage nodes or storage expansion enclosures.

The compute nodesand storage nodes share common resources, such as power, cooling, management, and I/O resources in the chassis.

Note

A 1-bay compute node occupies one node bay in the chassis.
A 1-bay compute node with captive-mode expansion node occupies two adjacent node bays (horizontally) in the chassis and requires the chassis shelf to be removed prior to installation.
A 2-bay compute node occupies two adjacent node bays (horizontally) in the chassis and requires the chassis shelf to be removed prior to installation.
A 4-bay storage node or storage expansion enclosure occupies four adjacent node bays (two vertically and horizontally) in the chassis and requires the chassis shelves and shelf supports to be removed prior to installation.

The Flex System Enterprise Chassis can support the following components:

Up to fourteen 1-bay compute nodes or up to seven 2-bay compute nodes with the shelves removed.
Up to seven 1-bay compute nodes with captive-mode expansion node (each assembly occupies two node bays).
Up three 4-bay storage nodes or storage expansion enclosures with the shelves and shelf supports removed.
Up to six power supplies. 200-240 V ac power supplies, 240-380 V dc power supplies, and -48 V to -60 V dc power supplies are available.
Up to ten fan modules (two 40 mm fan modules and eight 80 mm fan modules).
Four I/O modules (two redundant pairs), with the following features in each module:
- A four-lane physical interconnect that supports speeds up to 16 Gbps, four-lanes to each single node bay or eight-lanes to each full-width node bay (two adjacent bays), 16 Gbps per lane. The four lanes support 4x10 Gbps (40 Gbps) or Fourteen Data Rate InfiniBand at 56 Gbps.
- Four x1 ports or a single x4 port on each compute node
- Up to 16 logical I/O modules (four per physical I/O module)
One Flex System Manager management node, which provides multiple-chassis management support.
Two Lenovo Flex System Chassis Management Modules (CMMs) for redundancy. A CMM provides single-chassis management support.
Two fan logic modules, which detect fan module presence and provide a communication path to the fan modules.
Two fan distribution cards, which pass the power and signals from the midplane to the fan modules and the fan logic modules.
One rear LED card, which stores the vital product data (VPD) of the chassis components.

The chassis system provides the following features:

X-Architecture
The Flex System Enterprise Chassis is an X-Architecture system that uses proven innovative technologies to build powerful, scalable, and reliable compute node platforms. It provides features such as Predictive Failure Analysis (PFA) and real-time diagnostics.
Compute node expansion capabilities
You can install up to fourteen 1-bay compute nodes or seven 2-bay compute nodes in the chassis. Some compute nodes have connectors for additional optional devices that you can use to add capabilities to the compute nodes. For example, you can install optional I/O expansion adapters to add network interfaces or storage through the I/O modules.
Hot-swap capabilities
All component bays in the chassis are hot-swappable. For example, you can add, remove, or replace a compute node, I/O module, Flex System Manager management node, Chassis Management Module, fan logic module, fan module, or power supply without disconnecting the power from the chassis.
High-availability design
The following components in the chassis enable continued operation if one of the components fails:
- Power supplies
  The power supplies support a single power domain that provides dc power to all of the chassis components. If a power supply fails, the other power supplies can continue to provide power. For power redundancy, additional power supplies can be installed.
  Note
  The power management policy that you have implemented for the chassis determines the result of a power-supply failure.
- I/O modules
  The I/O module bays provide a four-lane physical interface to each 1-bay compute node that supports speeds up to 56 Gbps. The I/O modules must be installed in pairs if you want them to be redundant.
- Fan modules
  The fan modules provide cooling to all of the chassis components.
- Fan logic modules
  The fan logic modules enable the Chassis Management Module to monitor the fans and control fan speed.
Chassis midplane
The chassis midplane provides the following features:
- Redundant high-speed serialize/deserialize (SERDES) interconnects between compute nodes and I/O modules
- I2C communication paths between the CMM and all devices in the chassis
- 1 Gb Ethernet communication paths between the CMM and all compute nodes and I/O modules
- Power distribution to all nodes and modules
The midplane provides hot-swap connectors for the following components:
- Fourteen 1-bay compute nodes or seven 2-bay compute nodes
- Four I/O modules
- Two CMMs
- Six power supplies
- Ten fan modules
- Two fan logic modules
Systems management
If an Flex System Manager management node is installed, it provides configuration and management support for multiple chassis, their devices, and the compute nodes locally or remotely. For more information about the Flex System Manager, see the Flex System Manager information page.
The Lenovo Flex System Chassis Management Module (Chassis Management Module or CMM) provides single-chassis management. The Chassis Management Module is used to communicate with the system-management processor in each compute node to provide system monitoring, event recording, and alerts and to manage the chassis, its devices, and the compute nodes. The chassis supports up to two CMMs. If one CMM fails, the second CMM can detect its inactivity, activate itself, and take control of the system without any disruption. For more information about the CMM, see the CMM2 information page.

Table 1 shows the minimum component configuration that is required for the Flex System Enterprise Chassis to operate.

Table 1. Minimum chassis configuration.
The minimum chassis configuration table is a two-column table that lists the minimum number of components that must be installed in the Flex System Enterprise Chassis. Column 1 identifies the components and the minimum number of each component required. Column 2 identifies the chassis bay where the components are installed.
Component	Bay
Two power supplies	Power-supply bays 1 and 4
Two 40 mm fan modules	Fan bays 5 and 10
Four 80 mm fan modules	Fan bays 1, 2, 6, and 7
Two fan logic modules	Fan logic bays 1 and 2
Flex System Manager (optional, one per chassis)	Node bay 1
One Chassis Management Module	CMM bay 1
One I/O module	I/O bay 1
One compute node	Node bays 2 - 14

Record information about the Flex System Enterprise Chassis in Table 2. You will need this information for future reference.

Table 2. Chassis reference information.
The chassis reference information table allows you to record the specific model number and serial number of your Flex System Enterprise Chassis.
Chassis reference information
Product name	Flex System Enterprise Chassis
Machine type	7893, 8721, or 8724
Model number	_____________________________________________
Serial number	_____________________________________________

The serial number and model number are on the top, front, and rear of the chassis. The following illustration shows the location of the label on the front of the chassis.

Illustration showing the location of the serial number and model number.

If the chassis comes with an RFID tag, it is attached to the lower-right corner of the bezel. The following illustration shows the location of the RFID tag on the front of the chassis.

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