Lenovo 8721 User manual

Flex System Enterprise Chassis
Product Guide
Flex System is the next generation of blade technology with more performance and bandwidth and far
more capability to consolidate and virtualize than previous systems. Flex System is anchored by the Flex
System Enterprise Chassis which enables high-speed performance with integrated servers and
networking. Furthermore, its flexible design can meet the needs of varying workloads with independently
scalable IT resource pools for higher utilization and lower cost per workload.
The Flex System Enterprise Chassis is shown in Figure 1.
Figure 1. The Flex System Enterprise Chassis
Did you know?
In addition to the Flex System Enterprise Chassis, Lenovo also offers the Carrier-Grade Chassis for
installations requiring tolerance to higher temperatures or for use in environments without filtered air. For
information about the Carrier-Grade Chassis, see https://lenovopress.com/tips1285.
Flex System Enterprise Chassis 1

Key features
The Flex System Enterprise Chassis is a simple, integrated infrastructure platform that supports a mix of
compute, storage, and networking resources to meet the demands of your applications. The solution is
easily scalable with the addition of another chassis with the required nodes. With Lenovo XClarity
Administrator, multiple chassis can be monitored from a single screen. This flexible 14 node, 10U chassis
is designed for a simple deployment now and to scale to meet your needs in the future.
Flexibility and efficiency
The 14 bays in the chassis allow the installation of compute or management nodes, with networking
modules in the rear. A single chassis or a group of chassis can be fully customized to the specific needs of
the computing environment. IT can meet the needs of the business using a single system across multiple
operating environments.
The system monitors and manages power usage on all major chassis components so you have total
control over power consumption. Available power supply options are AC and -48V DC. AC power options
can be configurable in either a single or three-phase power domain. The chassis supports N+N or N+1
redundant power supplies and an entirely passive mid-plane to meet your reliability needs. The power
supplies are 80 PLUS Platinum-certified indicating high energy efficiency. The chassis design also
optimizes cooling with cooling zones within the chassis. The system manages the fan modules based on
node configuration within the chassis. So, the system can increase the speed of certain fan modules to
cool potential hot spots, and use lower speeds for other fan modules where appropriate.
Easily scalable with simple administration
Because the Flex System Enterprise Chassis is an all-in-one solution, it is designed for growth from a
single chassis to many. Adding compute, or networking capability is as simple as adding additional nodes
or modules. Compute nodes and I/O modules connect to a midplane and are designed to be inserted or
removed while the chassis is running. The use of the midplane means that the compute nodes and I/O
modules do not need their own power cables and do not need network cables or transceivers to connect
to each other within the chassis. These features make it easy to add or replace compute nodes and get
them operational quickly.
The simple, highly integrated management system allows you to use the Chassis Management Modules
integrated into each chassis to administer a single chassis, and the new Lenovo XClarity Administrator
offers agent-free hardware management for compute nodes and networking.
Designed for multiple generations of technology
The Flex System Enterprise Chassis is designed to be the foundation of your IT infrastructure now and into
the future. Compute performance requirements are always on the rise and networking demands continue
to grow with rising bandwidth needs and a shrinking tolerance for latency. The chassis is designed to
scale to meet the needs of your future workloads, offering the flexibility to support current and future
innovations in compute, storage, and networking technology.
Locations of key components and connectors
Flex System Enterprise Chassis 2

Locations of key components and connectors
The following figure shows the front of the Enterprise Chassis.
Figure 2. Front of the Flex System Enterprise Chassis
The following figure shows the rear of the Enterprise Chassis.
Figure 3. Rear of the Flex System Enterprise Chassis
Flex System Enterprise Chassis 3

Standard specifications
The following table lists the standard specifications.
Table 1. Standard specifications
Components Specification
Machine type 8721
Firmware Chassis with first generation Chassis Management Module (68Y7030): IBM-signed firmware
Chassis with Chassis Management Module 2 (00FJ669): Lenovo-signed firmware
Form factor 10U rack-mounted unit.
Maximum
number of
compute
nodes
14 half-wide (single bay), seven full-wide (two bays), three double-height full-wide (four bays) or
one quadruple-height full-wide (8 bays). Mixing is supported.
Chassis per
42U rack
Four.
Nodes per
42U rack
56 half-wide, or 28 full-wide.
Management Chassis Management Modules 2 (CMM2) modules provide chassis management. One or two
CMM2s standard, depending on the model and the use of two provides redundancy. Earlier
models of the Enterprise Chassis use the first generation CMM. The CMM2 interfaces with the
integrated management module (IMM2) integrated in each compute node in the chassis. Optional
Lenovo XClarity Administrator for hardware resource management with integrators to VMware
vCenter and Microsoft System Center, including virtualization, networking, and storage
management. Chassis with first generation CMM can be upgraded to CMM2 however CMM and
CMM2 cannot be mixed.
I/O
architecture
Up to eight lanes of I/O to an I/O adapter card, with each lane capable of up to 25 Gbps
bandwidth. Up to 16 lanes of I/O to a half-wide node with two adapters. A wide variety of
networking solutions, including Ethernet, Fibre Channel, Fibre Channel over Ethernet (FCoE), and
InfiniBand.
Power
supplies
Up to six power supplies that can provide N+N or N+1 redundant power. AC power supplies are
80 PLUS Platinum certified and provide over 94% efficiency at 50% load and 20% load. Each
power supply contains two independently powered 40 mm cooling fan modules. Power supply
options are 2500W AC and 2500W -48V DC power supplies. All installed power supplies must be
identical.
Fan modules Ten fan modules (eight 80 mm fan modules and two 40 mm fan modules); Four 80 mm and two
40 mm fan modules standard.
Dimensions Height: 440 mm (17.3 in)
Width: 447 mm (17.6 in)
Depth: 800 mm (31.5 in) (measured from front bezel to rear of chassis), 840 mm (33.1 in)
(measured from node latch handle to the power supply handle)
Weight Minimum configuration: 96.62 kg (213 lb)
Maximum configuration: 220.45 kg (486 lb)
Sound level 7.5 bels (declared)
Temperature Operating air temperature 5°C to 40°C
Electrical
power
AC Input power: 200 - 240 V ac (nominal), 50 or 60 Hz
-48 V DC Input power: -48V to -60 V dc (nominal)
Minimum configuration: 0.51 kVA (two power supplies)
Maximum configuration: 13 kVA (six power supplies)
Power
consumption
12,900 watts maximum
Flex System Enterprise Chassis 4

The following table lists what each standard model, Express model and TopSeller model includes. In
addition, each model ships with:
One C19 to C20 two-meter power cable for each power supply
One Rack Mount Kit
Models
The following table lists the specifications of the standard Enterprise Chassis models.
Table 2. Models
Model Node
bays
CMM*
(2 max)
I/O bays
(used / max)
I/O modules
included
Power
supplies
(6 max)
40mm
fans
(2 max)
80mm
fan
(8 max)
Console
breakout
cable
Standard models
8721-ALx 14 1x CMM2 0 / 4 None 2x 2500W 2 4 1
8721-DLx 14 1x CMM2 0 / 4 None 2x 2500W
-48V DC
241
TopSeller models – North America
8721-E3U 14 2x CMM2 2 / 4 2x SI4093# 6x 2500W 2 8 1
8721-E4U 14 2x CMM2 2 / 4 2x CN4093# 6x 2500W 2 8 1
8721-E5U 14 1x CMM2 0 / 4 None 2x 2500W 2 4 1
TopSeller models – Latin America & Brazil
8721-E3U 14 2x CMM2 2 / 4 2x SI4093# 6x 2500W 2 8 1
8721-E4U 14 2x CMM2 2 / 4 2x CN4093# 6x 2500W 2 8 1
* CMM1 = first generation Chassis Management Module (68Y7030), CMM2 = Chassis Management
Module 2 (00FJ669)
† Model B1x includes two Flex System EN4023 10Gb Scalable Switches, 94Y5212 and two Flex System
EN4023 10Gb Scalable Switch (FoD 3) upgrades, 47C9993. The FoD 3 upgrade enables FCoE on all active
ports of the switches.
‡ Model B2x includes two Flex System EN4023 10Gb Scalable Switches, 94Y5212 and two Lenovo Flex
System FC5022 24-port 16Gb SAN Scalable Switch, 00Y3324.
# Models E3U and E4U include two Flex System Fabric SI4093 System Interconnect Modules, 00FM518 or
two Flex System Fabric CN4093 10Gb Converged Scalable Switches, 00FM510, respectively.
Flex System Enterprise Chassis 5

Supported compute nodes
The following table lists the compute nodes that are supported in the Flex System Enterprise Chassis. The
table also lists the maximum number installable.
Table 3. Supported compute nodes and maximum quantities
Description Machine
type
Firmware
code base
Supported in chassis
8721 with CMM1
(IBM signed)
8721 with CMM2
(Lenovo signed)
Maximum
per chassis*
Lenovo ThinkSystem servers
ThinkSystem SN550 7X16 Lenovo signed No Supported 14
ThinkSystem SN850 7X15 Lenovo signed No Supported 7
Lenovo Flex System compute nodes
Flex System x220 7906 IBM signed Supported Supported 14
Flex System x222 7916 IBM signed Supported Supported 14
Flex System x240 7162 Lenovo signed No Supported 14
Flex System x240 8737 IBM signed Supported Supported 14
Flex System x240 M5
(E5-2600 v3)
9532 Lenovo signed Supported Supported 14
Flex System x240 M5
(E5-2600 v4)
9532 Lenovo signed No Supported 14
Flex System x440 7917 IBM signed Supported Supported 7
Flex System x440 7167 Lenovo signed Supported Supported 7
Flex System x280 X6 7196 Lenovo signed No Supported 7
Flex System x480 X6 7196 Lenovo signed Supported Supported 7
Flex System x880 X6 7196 Lenovo signed Supported Supported 7
Flex System x280 X6 7903 IBM signed Supported Supported 7
Flex System x480 X6 7903 IBM signed Supported Supported 7
Flex System x880 X6 7903 IBM signed Supported Supported 7
Flex System Manager 8731-A1x IBM signed Supported Supported 1**
IBM Power Systems servers
Flex System p24L 1457 IBM signed Supported No 14
Flex System p260 7895-22X IBM signed Supported No 14
Flex System p270 7954-24X IBM signed Supported No 14
Flex System p460 7895-42X IBM signed Supported No 7
† The maximum number of compute nodes supported depends on a number of factors. See below.
** A single Flex System Manager appliance can manage up to 16 chassis
The actual number of compute nodes systems that can be powered on in a chassis depends on these
factors:
The TDP power rating for the processors that are installed in the compute nodes (x86 servers)
The number of power supplies installed in the chassis
The capacity of the power supplies installed in the chassis (2100 W or 2500 W)
The power redundancy policy used in the chassis (N+1 or N+N)
Flex System Enterprise Chassis 6

For the x480 X6 or x880 X6, if two compute nodes are scaled together, then a maximum of 3 scaled
complexes can be installed. For the x880 X6, if four compute nodes are scaled together, then a maximum
of 1 scaled x880 X6 complexes can be installed. Other bays can be filled with other compute nodes.
The table in the Power Supplies section provides guidelines about what number of compute nodes can be
powered on in the Enterprise Chassis, based on the type and number of power supplies installed.
See ServerProven® for the latest information about the supported servers:
http://www.lenovo.com/us/en/serverproven/flexsystem.shtml
Supported I/O modules
The Flex System Enterprise Chassis has four high-speed switch bays that are capable of supporting a
variety of I/O architectures.
The switches are installed in switch bays in the rear of the Flex System Enterprise Chassis as shown in the
following figure. Switches are normally installed in pairs (bays 1 & 2, and bays 3 & 4), because I/O adapter
cards installed in the compute nodes route to two switch bays for performance and redundancy.
Figure 4. Location of the switch bays in the Flex System Enterprise Chassis
The following table lists the switches that are supported by the chassis.
Note: Some switches are withdrawn from marketing.
Flex System Enterprise Chassis 7

Table 4. I/O modules and upgrades
Description Part number
Firmware
code base
Supported in chassis
8721 with CMM
(IBM signed)
8721 with CMM2
(Lenovo signed)
25 Gb Ethernet module
ThinkSystem NE2552E Flex Switch 4SG7A08868 Lenovo† No Supported
40 Gb Ethernet module
EN6131 40Gb Ethernet Switch 90Y9346 Vendor Supported Supported
10 Gb Ethernet modules
EN4093R 10Gb Scalable Switch 00FM514 Lenovo† No Supported
CN4093 10Gb Converged Scalable Switch 00FM510 Lenovo† No Supported
SI4091 10Gb System Interconnect Module 00FE327 Lenovo† No Supported
SI4093 System Interconnect Module 00FM518 Lenovo† No Supported
EN4091 10Gb Ethernet Pass-thru 88Y6043 IBM† Supported Supported
EN4093 10Gb Scalable Switch 49Y4270* IBM† Supported Supported
EN4093R 10Gb Scalable Switch 95Y3309* IBM† Supported Supported
CN4093 10Gb Converged Scalable Switch 00D5823* IBM† Supported Supported
SI4093 System Interconnect Module 95Y3313* IBM† Supported Supported
Cisco Nexus B22 Fabric Extender 94Y5350 Vendor Supported Supported
EN4023 10Gb Scalable Switch 94Y5212* Vendor Supported Supported
1 Gb Ethernet switch
EN2092 1Gb Ethernet Scalable Switch 49Y4294 IBM† Supported Supported
Fibre Channel switches
FC5022 16Gb SAN Scalable Switch 88Y6374 Vendor Supported Supported
FC5022 24-port 16Gb SAN Scalable Switch 00Y3324 Vendor Supported Supported
FC5022 24-port 16Gb ESB SAN Scalable
Switch
90Y9356 Vendor Supported Supported
FC3171 8Gb SAN Switch 69Y1930 Vendor Supported Supported
FC3171 8Gb SAN Pass-thru 69Y1934* Vendor Supported Supported
InfiniBand switches
IB6131 InfiniBand Switch (QDR/FDR) 90Y3450 Vendor Supported Supported
* Withdrawn from marketing
† For these switches, IBM signed switch firmware is up to Version 7.x and Lenovo signed switch firmware
is Version 8.x onwards
Flex System Enterprise Chassis 8

I/O architecture
Each half-wide compute node (such as the ThinkSystem SN550) has two adapter slots, and each full-wide
compute node (such as the ThinkSystem SN850) has four adapter slots. The adapter slots in each
compute node route through the chassis midplane to the switch bays. The architecture supports up to
eight ports per adapter.
The following figure shows how two-port adapters are connected to switches installed in the chassis.
Figure 5. Logical layout of the interconnects between two-port I/O adapters and I/O modules
A four-port adapter doubles the connections between each adapter and switch pair (for example, a four-
port adapter in A1 in each compute node routes two connections to switch 1 and two connections to
switch 2).
The following figure shows how four-port adapters are connected to switches that are installed in the
chassis.
Flex System Enterprise Chassis 9

Figure 6. Logical layout of the inter-connections between four-port I/O adapters and I/O modules
The following table shows the connections between adapter slots in the compute nodes to the switch bays
in the chassis.
Notes:
To make use of all four ports of a four-port adapter across all blade servers, the switch must have
28 internal ports enabled, and two switches must be installed in the bays as indicated.
To make use of six ports of a eight-port adapter across all blade servers, the switch must have 42
internal ports enabled, and two switches must be installed in the bays as indicated. Ports 7 and 8
of an eight-port adapter are reserved for future use. The chassis supports all eight ports, but there
are no switches that are available that connect to these ports.
Flex System Enterprise Chassis 10

Table 5. Adapter to I/O bay correspondence
I/O adapter slot
in the server Port on the adapter*
Corresponding I/O module bay
in the chassis
Bay 1 Bay 2 Bay 3 Bay 4
Slot 1 Port 1 Yes No No No
Port 2 No Yes No No
Port 3 (for 4 & 8-port cards) Yes No No No
Port 4 (for 4 & 8-port cards) No Yes No No
Port 5 (for 8-port cards) Yes No No No
Port 6 (for 8-port cards) No Yes No No
Port 7 (for 8-port cards) Yes No No No
Port 8 (for 8-port cards) No Yes No No
Slot 2 Port 1 No No Yes No
Port 2 No No No Yes
Port 3 (for 4 & 8-port cards) No No Yes No
Port 4 (for 4 & 8-port cards) No No No Yes
Port 5 (for 8-port cards) No No Yes No
Port 6 (for 8-port cards) No No No Yes
Port 7 (for 8-port cards) No No Yes No
Port 8 (for 8-port cards) No No No Yes
Chassis Management Module
The Chassis Management Module (CMM) provides single-chassis management in the Enterprise Chassis.
The CMM is used to communicate with the integrated management module (IMM) controller 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 has one CMM installed standard but supports two CMMs for redundancy. If one CMM fails,
the second CMM can detect its inactivity and activate itself to take control of the system without any
disruption. The CMM is central to the management of the chassis and is required in the Enterprise
Chassis.
There are two versions of the Chassis Management Module available:
Chassis Management Module 2 (00FJ669) -- contains a Trusted Platform Module (TPM) v2.0 chip
and has a Lenovo-signed firmware codebase. This module is recommended for new installation.
First generation Chassis Management Module (68Y7030) -- contains a Trusted Platform Module
(TPM) v1.1 chip and has an IBM-signed firmware codebase
Standard and TopSeller models of the chassis contain either a CMM (68Y7030) or a CMM2 (00FJ669) as
listed in Table 2. The selection of CMM determines which compute nodes and I/O modules are supported
in the chassis. See Tables 3 and 4 respectively for details. You can replace a CMM with a CMM2, however
mixing is not supported -- you cannot have a chassis with one CMM (68Y7030) and one CMM2 (00FJ669).
Flex System Enterprise Chassis 11

The following table shows the ordering information.
Table 6. Chassis Management Module
Part
number
Feature codes* Description Standard /
Maximum
68Y7030 A0TM / A0UE Flex System Chassis Management Module 1 / 2
00FJ669 ASPT / ASQ8 Flex System Chassis Management Module 2 1 / 2
* The first feature code corresponds to the base CMM installed in the chassis. The second feature code
corresponds to the optional second CMM which provides redundancy.
The following figure shows the Chassis Management Module. See Figure 3 for the location of the CMM in
the chassis.
Figure 7. Chassis Management Module
The CMM provides these functions:
Power control
Fan management
Chassis and compute node initialization
Switch management
Diagnostics: chassis, I/O options, and compute nodes
Resource discovery and inventory management
Resource alerts and monitoring management
Chassis and compute node power management
Security policy management
Role-based access control
Support for up to 84 local CMM user accounts
Support for up to 32 simultaneous sessions
Flex System Enterprise Chassis 12

The CMM has the following connectors:
USB connection. This connection can be used for insertion of a USB media key for tasks, such as
firmware updates.
10/100/1000 Mbps RJ45 Ethernet connection to connect to a management network. The CMM can
be managed via this Ethernet port.
Serial port (mini-USB) for local command-line interface (CLI) management. Use serial cable 90Y9338
for connectivity.
The CMM has the following light-emitting diodes (LEDs) that provide the following information:
Power-on LED
Activity LED
Error LED
Ethernet port link and port activity LEDs
The CMM also incorporates a reset button, which, when pressed, resets the CMM back to its default
condition. It has two functions, depending on how long the button is pressed:
When pressed for less than 5 seconds, the CMM restarts.
When pressed for more than 5 seconds (for example, 10 or 15 seconds), the CMM configuration is
reset to the manufacturing defaults, and then the CMM restarts.
The CMM supports a web-based graphical user interface (GUI) that provides a way to perform CMM
functions within a supported web browser. You can also perform management functions through the CMM
command-line interface (CLI). Both the web-based GUI and the CLI are accessible via the single RJ45
Ethernet connector on the CMM or from any other system that is connected to the same (management)
network.
The CMM has the following default static IPv4 address. By default, the CMM is configured to respond to
Dynamic Host Configuration Protocol (DHCP) first before using its static IPv4 address:
IP address: 192.168.70.100
Subnet: 255.255.255.0
User ID: USERID (all capital letters)
Password: PASSW0RD (all capital letters, with a zero instead of the letter O)
The CMM does not have a fixed static IPv6 IP address, by default. Initial access to the CMM in an IPv6
environment can be performed by either using the IPv4 IP address or the IPv6 link-local address. The IPv6
link-local address is automatically generated based on the Media Access Control (MAC) address of the
CMM.
The CMM is the key component enabling the integrated management network. Internally, the CMM has a
multiple port L2 1Gigabit Ethernet switch with dedicated links to all 14 node bays, all four switch bays, and
the second CMM, if installed. These connections are all point-to-point, ensuring dedicated bandwidth. The
1GbE links are full-duplex, fixed speed (not auto-negotiate) links. The 1 GbE management network is only
accessible by each node's management controller (IMMv2 or FSP), each switch module's management
interfaces, the CMM, and the Flex System Manager (FSM) management appliance. This design permits the
separation of the management network from the data network.
Flex System Enterprise Chassis 13

The CMM has a high-security policy that is enabled by default, which means that the following policies are
enabled by default:
Strong password policies with automatic validation and verification checks
Required update of the default passwords after the initial setup
Only secure communication protocols, such as SSH and SSL. Unencrypted protocols, such as
HTTP, Telnet, and SNMPv1, are disabled.
Certificates to establish secure, trusted connections for applications that run on the management
processors
Lenovo XClarity Administrator
Lenovo XClarity Administrator is centralized resource management solution aimed at reducing complexity,
speeding response and enhancing availability of both Lenovo server systems and solutions.
Lenovo XClarity Administrator provides agent-free hardware management for System x rack servers and
Flex System compute nodes and components, including the Chassis Management Module and Flex
System I/O modules. The following figure shows the Lenovo XClarity Administrator interface, where both
Flex System components and rack servers are being managed and can be seen on the dashboard.
Figure 8. Lenovo XClarity Administrator dashboard
For information about Lenovo XClarity Administrator, see the Lenovo Press Product Guide:
http://lenovopress.com/tips1200
Power supplies
A maximum of six hot-swap power supplies can be installed in the Enterprise Chassis. In models where
only two power supplies are standard, additional power supplies are orderable per the following table. All
installed power supplies must be the same.
Flex System Enterprise Chassis 14

Note: The following power supplies are withdrawn from marketing:
2100W Power Module, 47C7633
HVDC 2500W Power Module, 00AM765
Table 7. Ordering part number and feature code
Description Part number Feature code
Flex System Enterprise Chassis 2500W Power Module 43W9049 A0UC
Flex System Enterprise Chassis -48V DC 2500W Power Module 00FJ635 A5VC
Each AC power supply part number ships with one 2.0m (6.5 ft) 16A/100-250V, C19 to IEC 320-C20 rack
power cable, feature 6292. Other supported AC line cords including three-way split line cords, are listed in
the following table.
Table 8. Supported AC line cords
Description Part number Feature code
4.3m, 16A/208V, C19 to NEMA L6-20P (US) Line Cord 40K9772 6275
2.5m, 16A/100-240V, C19 to IEC 320-C20 Rack Power Cable 39Y7916 6252
2m, 16A/100-250V, C19 to IEC 320-C20 Rack Power Cable None 6292
4.3m, US/CAN, NEMA L15-30P - (3P+Gnd) to 3X IEC 320 C19 00D7192 A2Y3
4.3m, EMEA/AP, IEC 309 32A (3P+N+Gnd) to 3X IEC 320 C19 00D7193 A2Y4
4.3m, A/NZ, (PDL/Clipsal) 32A (3P+N+Gnd) to 3X IEC 320 C19 00D7194 A2Y5
The -48V DC power supply operates at -48V to -60 V dc (nominal) and has a Molex 1060 Power
Connector. The power supply ships with one 2.0m DC power cord (FRU part number 69Y1652)
The following figure shows the power supply and highlights the light-emitting diodes (LEDs).
Figure 9. Power supply option
The AC power supplies are 80 PLUS Platinum-certified. The 2500W modules are 2500 Watts output rated
at 200VAC to 208VAC (nominal), and 2750W at 220VAC to 240VAC (nominal). The power supply has an
oversubscription rating of up to 3538 Watts output at 200VAC. The power supply operating range is 200-
240 VAC. The power supplies also contain two dual independently powered 40mm cooling fan modules
that are powered not from the power supply itself, but from the chassis midplane. The fan modules are
variable speed and controlled by the chassis fan logic.
Flex System Enterprise Chassis 15

80 PLUS is a performance specification for power supplies used within servers and computers. To meet
the 80 PLUS standard, the power supply must have an efficiency of 80% or greater, at 20%, 50%, and
100% of rated load with PF of .09 or greater. The standard has several grades, such as Bronze, Silver,
Gold, and Platinum. More information on 80 PLUS is available at http://www.80PLUS.org
The chassis allows configurations of power supplies to give N+N or N+1 redundancy. A chassis can
operate on only three power-supply units (PSUs) with no redundancy, but N+1 or N+N is advised. Three
power supplies (or six with N+N redundancy) allow for a balanced three-phase configuration.
All power supply modules are combined into a single power domain within the chassis, which distributes
power to each of the compute nodes, I/O modules, and ancillary components through the Enterprise
Chassis midplane. The midplane is a highly reliable design with no active components. Each power supply
is designed to provide fault isolation and is hot swappable.
In the case of the 2500W supplies, power monitoring of both the DC and AC signals allows the Chassis
Management Module to accurately monitor the power supplies.
The following figure shows the compute node bay numbering (left) and power supply bay numbering
(right).
Figure 10. Power supply bay numbering
The following table shows the number of compute nodes that are supported in the chassis based on the
power supplies used (2100W or 2500W), the number of power supplies installed, and the power
redundancy policy enabled (N+1 or N+N).
Note: 2100W power supplies are now withdrawn from marketing.
In this table, the colors of the cells have the following meaning:
Green cell: Supported with no restrictions as to the number of compute nodes that can be installed
Yellow cell: Supported but with restrictions on the number of compute nodes that can be installed.
Note: These tables assume the chassis is filled with idential compute nodes. For more complex
configurations, use the Power Configurator:
https://support.lenovo.com/documents/LNVO-PWRCONF
Flex System Enterprise Chassis 16

Table 9. Specific number of compute nodes supported based on installed power supplies
CPU
TDP
2100W power supplies* 2500W power supplies
N+1, N=5
6 total
N+1, N=4
5 total
N+1, N=3
4 total
N+N, N=3
6 total
N+1, N=5
6 total
N+1, N=4
5 total
N+1, N=3
4 total
N+N,
N=3
6 total
ThinkSystem SN550
70 W 14 14 11 11 14 14 14 14
85 W 14 14 11 11 14 14 14 14
105 W 14 14 11 11 14 14 14 14
125 W 14 14 11 11 14 14 13 14
130 W 14 13 11 11 14 14 12 13
140 W 14 13 11 11 14 14 12 13
150 W 14 12 11 11 14 14 12 12
165 W 14 12 11 11 14 14 11 12
ThinkSystem SN850
85 W 7 7 5 5 7 7 7 7
105 W 7 7 5 5 7 7 7 7
125 W 7 7 5 5 7 7 6 7
130 W 7 6 5 5 7 7 6 6
140 W 7 6 5 5 7 7 6 6
150 W 7 6 5 5 7 7 6 6
165 W 7 6 5 5 7 7 5 6
Flex System x220
50 W 14 14 14 14 14 14 14 14
60 W 14 14 14 14 14 14 14 14
70 W 14 14 14 14 14 14 14 14
80 W 14 14 14 14 14 14 14 14
95 W 14 14 14 14 14 14 14 14
Flex System x222
50 W 14 14 13 14 14 14 14 14
60 W 14 14 12 12 14 14 14 14
70 W 14 14 11 12 14 14 14 14
80 W 14 14 10 11 14 14 13 14
95 W 14 13 9 10 14 14 12 13
Flex System x240
60 W 14 14 11 11 14 14 14 14
70 W 14 14 11 11 14 14 14 14
80 W 14 14 11 11 14 14 14 14
95 W 14 14 11 11 14 14 14 14
115 W 14 14 11 11 14 14 14 14
130 W 14 14 11 11 14 14 13 14
135 W 14 14 11 11 14 14 13 14
Flex System Enterprise Chassis 17

Flex System x240 M5
52 W 14 14 11 11 14 14 14 14
55 W 14 14 11 11 14 14 14 14
65 W 14 14 11 11 14 14 14 14
75 W 14 14 11 11 14 14 14 14
85 W 14 14 11 11 14 14 14 14
90 W 14 14 11 11 14 14 14 14
105 W 14 14 11 11 14 14 13 14
120 W 14 14 11 11 14 14 13 14
135 W 14 13 11 11 14 14 12 13
145 W 14 13 11 11 14 14 12 13
Flex System x440
95 W 7 7 6 6 7 7 7 7
115 W 7 7 5 5 7 7 7 7
130 W 7 7 5 5 7 7 6 7
Flex System x880 X6, x480 X6 and x280 X6
105 W 7 7 5 5 7 7 7 7
130 W 7 7 5 5 7 7 7 7
155 W 7 7 5 5 7 7 7 7
Flex System V7000 Storage Node
N/A33333333
Flex System p24L
All 14 12 9 10 14 14 12 13
Flex System p260
All 14 12 9 10 14 14 12 13
Flex System p270
All 14 12 9 9 14 14 12 12
Flex System p460
All76457766
CPU
TDP
2100W power supplies* 2500W power supplies
N+1, N=5
6 total
N+1, N=4
5 total
N+1, N=3
4 total
N+N, N=3
6 total
N+1, N=5
6 total
N+1, N=4
5 total
N+1, N=3
4 total
N+N,
N=3
6 total
* The 2100W Power Module, part number 47C7633, is withdrawn from marketing
Flex System Enterprise Chassis 18

Fan modules
The Enterprise Chassis supports up to a total of ten hot-swap fan modules: two 40 mm (1.57 in) fan
modules and eight 80 mm (3.14 in) fan modules.
The two 40 mm fan modules distribute airflow to the I/O modules and chassis management modules. Both
of these fan modules ship with the chassis. The 80 mm fan modules distribute airflow to the compute
nodes through the chassis from front to rear. Each 80 mm fan module actually contains two 80 mm fan
modules, back to back at each end of the module, which are counter-rotating. The following figure shows
the 80 mm fan module.
Figure 11. 80 mm fan module
Four 80 mm fan modules are installed standard in chassis model 8721-A1x and CTO orders. The
maximum number of 80 mm fan modules that can be installed is eight. Ordering information is shown in
the following table. When the modules are ordered as a part number, they are supplied as a pair. The
feature codes is comprised of one fan.
Table 10. Fan module ordering information
Description Part number Feature code
Flex System Enterprise Chassis 80mm Fan Module 43W9078
(2 fan modules)
A0UA
(1 fan module)
The 80 mm fan modules are populated, depending on the nodes installed. To support the base
configuration and up to four nodes, chassis model 8721-A1x ships with four 80 mm fan modules and two
40 mm fan modules preinstalled. There are two cooling zones for the nodes: a left zone and a right zone.
Fan modules must be installed in pairs as shown in the following figure. If there are insufficient fan
modules for the number of nodes installed, the compute nodes might be throttled to balance heat
generation and cooling capacity.
Flex System Enterprise Chassis 19

Figure 12. Fan module locations and cooling zones
The 40 mm fan modules are always required. Additional 80 mm fan modules are required as listed in the
following table.
Table 11. 80 mm fan module requirements
Description 80 mm fan module requirements
Up to four half-wide compute nodes (node bays 1 - 4) 4 fan modules (fan bays 1, 2, and 6, 7)
Up to eight half-wide compute nodes (node bays 1 - 8) 6 fan modules (fan bays 1, 2, 3 and 6, 7, 8)
All 14 compute node bays (node bays 1 - 14) 8 fan modules (fan bays 1, 2, 3, 4 and 6, 7, 8, 9)
Physical specifications
Dimensions:
Height: 440 mm (17.3 inches)
Width: 447 mm (17.6 in)
Depth, measured from front bezel to rear of chassis: 800 mm (31.5 in)
Depth, measured from node latch handle to the power supply handle: 840 mm (33.1 in)
Weight:
Minimum configuration: 96.62 kg (213 lb)
Maximum configuration: 220.45 kg (486 lb)
Shipping dimensions (approximate):
Height: 81 cm (32 in)
Length: 102 cm (40 in)
Width: 71 cm (24 in)
Supported environment
Flex System Enterprise Chassis 20