Managing the Switch

Displaying Information About the Installed Hardware Modules

Use the show hardware command to display information about the switch hardware and the hardware modules that are installed in the switch chassis.

Displaying the Hardware Inventory for a Switch

Use the show inventory command to display information about the field replaceable units (FRUs), including product IDs, serial numbers, and version IDs. The output for this command displays information about modules that respond to command line interface (CLI) commands. The modules are supervisors, system controllers, line cards, fans, fabric modules, and power supplies. The CLI commands do not display information for modules that do not respond to those commands, such as blank modules that cover empty slots to manage airflow.

Displaying the Backplane and Serial Number Information

Use the show sprom backplane command to display the backplane information, including the serial number for the switch.

Displaying Environmental Information for the Switch

Use the show environment command to display all the environment-related switch information. 

switch# show environment
Power Supply:
Voltage: 12.0 Volts
 
Power                              Actual        Total
Supply    Model                    Output     Capacity    Status
                                 (Watts )     (Watts )
-------  -------------------  -----------  -----------  --------------
1        N9K-PAC-3000W-B              0 W       3000 W       shut    
2        ------------               N/A W          0 W      Absent   
3        N9K-PAC-3000W-B           1277 W       3000 W        ok     
4        ------------               N/A W          0 W      Absent   
5        ------------               N/A W          0 W      Absent   
6        ------------               N/A W          0 W      Absent   
7        N9K-PUV-3000W-B           1312 W       3000 W        ok     
8        ------------               N/A W          0 W      Absent   
9        ------------               N/A W          0 W      Absent   
10       ------------               N/A W          0 W      Absent   
 
 
 
                                   Actual        Power     
Module     Model                     Draw    Allocated    Status
                                  (Watts )     (Watts )    
--------  -------------------  -----------  -----------  --------------
1         N9K-X9736C-FX              398 W        720 W    Powered-Up 
2         N9K-X9736C-FX              381 W        900 W    Powered-Up 
22        N9K-C9516-FM-E2            414 W        720 W    Powered-Up 
24        N9K-C9516-FM-E2            377 W        720 W    Powered-Up 
26        N9K-C9516-FM-E2            378 W        720 W    Powered-Up 
27        N9K-SUP-A                   56 W         72 W    Powered-Up 
29        N9K-SC-A                    12 W         24 W    Powered-Up 
30        N9K-SC-A                    12 W         24 W    Powered-Up 
fantray1  N9K-C9516-FAN               83 W        444 W    Powered-Up 
fantray2  N9K-C9516-FAN               86 W        444 W    Powered-Up 
fantray3  N9K-C9516-FAN               84 W        444 W    Powered-Up 
 
N/A - Per module power not available
 
 
Power Usage Summary:
--------------------
Power Supply redundancy mode (configured)                Non-Redundant(combined)
Power Supply redundancy mode (operational)               Non-Redundant(combined)
 
Total Power Capacity (based on configured mode)               6000 W
Total Power of all Inputs (cumulative)                        6000 W
Total Power Output (actual draw)                              2589 W
Total Power Allocated (budget)                                5168 W
Total Power Available for additional modules                  831  W
switch#

Displaying the Current State of a Module

Use the show module command to display information about modules that are installed in the switch chassis. This information includes module type, bootup status, MAC addresses, serial numbers, software versions, and hardware versions. Use this command to display information about all the installed modules or a specific module.

  • For information on all modules, use the show module command.

  • For information on a specific supervisor, system controller, line card, or fabric module, use the show module slot_number command to specify a slot number.


    Note

    To determine the slots to specify, use the show inventory command. This command reports on only software-controlled modules such as supervisors, system controllers, line cards, fabric modules, fan trays, and power supplies. It does not report on modules that are not software controlled, such as blank modules installed in empty slots to control airflow.

This table provides descriptions of the module status that is displayed with the show module commands.

Device Line Card State Status String syslog Description

Line card/FM

powered up

powered-up

PLATFORM-2-MOD_PWRUP: Module 1 powered up (Serial number#)

The hardware has electrical power. When the hardware is powered up, the software begins booting.

Line card/FM

testing

testing

No syslog

The module has established connection with the supervisor and the module is performing bootup diagnostics.

Line card/FM

initializing

initializing

No syslog

The diagnostics have completed successfully and the configuration is being downloaded.

Line card/FM

failure

failure

MODULE-2-MOD_DIAG_FAIL: Module 1 (Serial number:#) reported failure due to Service on linecard had a hap-reset in device DEV_SYSMGR (device error 0x335)

The switch detects a module failure upon initialization and automatically attempts to power-cycle the module three times. After the third attempt, the module powers down.

Line card/FM

ok

ok

MODULE-5-MOD_OK: Module # is online (Serial number:#)

The switch is ready to be configured.

Line card/FM

power-denied

pwr-denied

PLATFORM-2-MOD_PWRDENY: Module # can not be powered up due to insufficient power (Serial number#)

The switch detects insufficient power for a line card to power up.

Line card/FM

power-denied

pwr-denied

PLATFORM-2-MOD_PWRDENY: Module # can not be powered up due to insufficient power (Serial number#)

The switch detects insufficient power for a line card to power up.

Line card/FM

Powered down

powered-dn

PLATFORM-2-MOD_PWRDN: Module # powered down (Serial number#)

Module is powered down by user.

Line card/FM

Detected

present

PLATFORM-2-MOD_DETECT: Module # detected (Serial number#)

Module is powered up and is detected.

Line card/FM

Inserted

inserted

No syslog

Module is inserted.

Line card/FM

Power cycled /rebooted

pwr-cycld

No syslog

Module is rebooted.

active

active

This module is the active supervisor or system controller module and the switch is ready to be configured.

Supervisor Module

Active

active*

MODULE-5-ACTIVE_SUP_OK: Supervisor 27 is active (Serial number:#)

This module is the active supervisor or system controller module and the switch is ready to be configured.

Supervisor Module

HA-standby

ha-standby

MODULE-5-STANDBY_SUP_OK: Supervisor 28 is standby

The HA switchover mechanism is enabled on the standby supervisor module.

Supervisor Module

powered up

powered-up

The switchover mechanism is enabled on the standby system controller module.

System Controller

Standby

standby

MODULE-5-MOD_OK: Module 29 is online (Serial number:#)

The system controller is on standby.

System Controller

Active

active

MODULE-5-MOD_OK: Module 29 is online (Serial number:#)

The system controller is active.

System Controller

Power cycled/rebooted

 pwr-cycld

No Syslog

The system controller is rebooted.

Use the show module [slot_number] command to display information about all the installed modules or for the module that you specify by its slot number.


Note

This example shows how to display information about a module in a specific slot (slot 4) of the chassis. 

switch# show module 4
Mod  Ports  Module-Type                         Model              Status
---  -----  ----------------------------------- ------------------ ----------
4    36     36p 40G Ethernet Module             N9k-X9636PQ        ok

Mod  Sw              Hw
---  --------------  ------
4    6.1(4.11)       0.1010  


Mod  MAC-Address(es)                         Serial-Num
---  --------------------------------------  ----------
4    00-22-bd-f8-2a-83 to 00-22-bd-f8-2a-b6  SAL17257AHD
switch#

Displaying Temperatures for a Module

Use the show environment temperature command to display temperature readings for module temperature sensors. System controllers, supervisors, line cards, and fabric modules have temperature sensors with two thresholds.

  • Minor temperature threshold—When a minor threshold is exceeded, a minor alarm occurs and these actions occur for all four sensors:

    • Displays system messages

    • Sends Call Home alerts (if configured)

    • Sends SNMP notifications (if configured)

  • Major temperature threshold—When a major threshold is exceeded, a major alarm occurs and these actions occur:

    • For sensors 1, 3, and 4 (outlet and on-board sensors), these actions occur:

      • Displays system messages.

      • Sends Call Home alerts (if configured).

      • Sends SNMP notifications (if configured).

    • For sensor 2 (intake sensor), these actions occur:

      • If the threshold is exceeded in a switching module, only that module is shut down.

      • If the threshold is exceeded in an active supervisor module with HA-standby or standby present, only that supervisor module is shut down and the standby supervisor module takes over.

      • If you do not have a standby supervisor module in your switch, you have up to 2 minutes to decrease the temperature. During this interval, the software monitors the temperature every 5 seconds and continuously sends system messages as configured.


        Tip

        We recommend that you install dual supervisor modules. If you are using a switch without dual supervisor modules, we recommend that you immediately replace the fan module if just one fan is not working.


Note

A threshold value of –127 indicates that no thresholds are configured or applicable.


Note

This command reports on only software-controlled modules, such as supervisors, system controllers, line cards, fabric modules, fan trays, and power supplies. It reports on modules that are not controlled by software, such as blank modules installed in empty slots to control airflow.

Use the show environment temperature command to display the temperature readings for each of the powered-up modules. 

switch# show environment temperature
Temperature:
--------------------------------------------------------------------
Module   Sensor        MajorThresh   MinorThres   CurTemp     Status
                       (Celsius)     (Celsius)    (Celsius)         
--------------------------------------------------------------------
4        CPU             105             95          32         Ok             
4        TD2-1           105             95          41         Ok             
4        TD2-2           105             95          41         Ok             
4        TD2-3           105             95          41         Ok             
4        VRM-1           110             100         41         Ok             
4        VRM-2           110             100         45         Ok             
4        VRM-3           110             100         40         Ok             
22       CPU             105             95          34         Ok             
22       TD2-1           105             95          45         Ok             
22       TD2-2           105             95          41         Ok             
22       VRM-1           110             100         49         Ok             
22       VRM-2           110             100         47         Ok             
27       OUTLET          75              55          29         Ok             
27       INLET           60              42          20         Ok             
27       CPU             90              80          27         Ok             
28       OUTLET          75              55          27         Ok             
28       INLET           60              42          22         Ok             
28       CPU             90              80          33         Ok             
29       CPU             105             95          40         Ok             
30       CPU             105             95          34         Ok             
switch#

Connecting to a Module

Use the attach module slot_number command to connect to any module. When the module prompt appears, obtain further details about the module by using module-specific commands in EXEC mode.

Use the attach module command to display the standby supervisor module information, although you cannot configure the standby supervisor module using this command.


Note

To see which slots are filled with modules, use the show inventory command.

Use the attach module slot_number command to get direct access to a specific module.

This example shows how to attach to the supervisor in slot 28. 

switch# attach module 28
Attaching to module 28 ...
To exit type 'exit', to cancel type '$.' 
Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Copyright (c) 2002-2013, Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained in this software are
owned by other third parties and used and distributed under
license. Certain components of this software are licensed under
the GNU General Public License (GPL) version 2.0 or the GNU
Lesser General Public License (LGPL) Version 2.1. A copy of each
such license is available at
http://www.opensource.org/licenses/gpl-2.0.php and
http://www.opensource.org/licenses/lgpl-2.1.php
switch(standby)#

Note

To exit the module-specific prompt, use the exit command.


Tip

If you are not accessing the switch from a console terminal, this command is the only way to access the standby supervisor module.


Note

This command reports on only software-controlled modules, such as supervisors, system controllers, line cards, fabric modules, fan trays, and power supplies. It reports on modules that are not controlled by software, such as blank modules installed in empty slots to control airflow.

Saving the Module Configuration

Use the copy running-config startup-config command from EXEC mode to save the new configuration to nonvolatile storage. Once you enter this command, the running and the startup copies of the configuration are identical.

This table lists various scenarios when module configurations are preserved or lost.

Scenario

Result

A particular switching module is removed and you used the copy running-config startup-config command.

The configured module information is lost.

A particular switching module is removed and a different switching module is replaced and you used the copy running-config startup-config command.

The configured module information is lost.

A particular switching module is removed and the same switching module is replaced before you enter the copy running-config startup-config command again.

The configured module information is preserved.

A particular switching module is removed and replaced with the same type switching module, and you entered the reload module slot_number command.

The configured module information is preserved.

A particular switching module is reloaded when you enter the reload module slot_number command.

The configured module information is preserved.

Shutting Down or Starting Up a Module

To shut down a module, use the poweroff module command to specify the module by its slot number in the chassis.

To power up a module, use the no poweroff module command to specify the module by its slot number in the chassis.


Note

To determine the slot number for a module, use the show inventory command.


Note

Use this command with software-controlled modules, such as supervisors, system controllers, line cards, fabric modules, fan trays, and power supplies. It does not work with modules that are not controlled by software, such as blank modules installed in empty slots to control airflow.

Procedure

Step 1

Use the configure terminal to enter the global configuration mode.

Example:

switch# configure terminal
switch(config)#

Step 2

Enter the [no] poweroff module slot_number command to shut down (or alternatively power up) a specific module.

Example:

switch(config)# poweroff module 3
switch(config)#

Example:

switch(config)# no poweroff module 3
switch(config)#

Purging a Nonfunctioning Module from the Running Configuration

Verify that either the system controller, line card, or fabric slot is empty or that the module that is installed in the slot is powered down.

Clear the running configuration for a system controller, line card, or fabric slot (slots 1 to 30) that is not functioning. To clear the configuration, use the purge module command in EXEC mode.


Note

This command does not work on supervisor slots or on any line card slot that currently has a powered-up module or on blank modules. Use the purge module slot_number runnning-config command to clear the running configuration for the specified line card slot. 

switch# purge module 4 running-config

For example, suppose that you create an IP storage configuration with a line card in slot 3 of Switch A. This module uses an IP address. You decide to remove this line card module and move it to Switch B, and you no longer need the IP address. If you try to configure this unused IP address, you receive an error message that prevents you from proceeding with the configuration. In this case, you enter the purge module 3 running-config command to clear the old configuration in Switch A, before using the IP address.

Displaying Power Usage Information

To display the power usage information for the entire switch, use the show environment power command. This command shows the power usage for the power consuming modules that are installed in the switch.


Note

Power usage is reserved for both supervisor modules, regardless of whether one or both supervisor modules are present.

Use the show environment power command to display power usage information for the switch.

Reload a Module

To reset a module, use the reload module slot_number command and specify the module by its slot number in the chassis.


Caution

Reloading a module disrupts traffic through the module.


Note

To see which slots are filled with modules, use the show inventory command.


Note

These commands report on only software-controlled modules, such as supervisors, system controllers, line cards, fabric modules, fan trays, and power supplies. Modules that are uncontrolled by software, such as blank modules installed in empty slots to control airflow are not reported on.

Procedure

Step 1

Use the configure terminal command to enter the global configuration mode.

Example:

switch# configure terminal
switch(config)#

Step 2

Use the reload module slot_number command to specify the slot number of the module to reset.

Example:

switch(config)# reload module 4
This command will reload module 4. Proceed[y/n]?  [n] y
reloading module 4 ...
switch(config)#

Rebooting a Switch

To reboot or reload the switch, use the reload command without any options.


Note

Save the running configuration first. If you use the reload command, use the copy running-config startup-config command.

Procedure

Step 1

Use the configure terminal command to enter the global configuration mode.

Example:

switch# configure terminal
switch(config)#

Step 2

Use the copy running-config startup-config command to save the running configuration.

Example:

switch(config)# copy running-config startup-config

Step 3

Use the reload command to reload the switch.

Example:

switch(config)# reload

Overview of Supervisor Modules

The switch has one or two supervisor modules of these types:

  • Supervisor A (N9K-SUP-A) modules with four cores, 4 executable threads, 16 GB of memory, and 64 GB of SSD)

  • Supervisor A+ (N9K-SUP-A+) with four cores, 8 executable threads, 1.8 GHz, 16 GB of memory, and 64 GB of SSD

  • Supervisor B (N9K-SUP-B) with six cores, 12 executable threads, 2.2 GHz, 24 GB of memory, and 256 GB of SSD

  • Supervisor B+ (N9K-SUP-B+) with six cores, 12 executable threads, 1.9 GHz, 32 GB of memory, and 256 GB of SSD

When a switch has two supervisors, one supervisor is automatically active while the other is in standby mode. If the active supervisor goes down or is disconnected for replacement, the standby supervisor automatically becomes active. If you replace one of two installed supervisor modules with another module, you can do so without interrupting operations. The supervisor that you are not replacing becomes the active supervisor and retains the kickstart configuration while you replace the other supervisor. If the switch has just one supervisor, you can install the new supervisor in the open supervisor slot during operations. Make that supervisor active after the installation.


Note

If there are two supervisors that are installed in the chassis, both must be the same type as shown in this table:

Table 1.

Active Supervisor

Standby Supervisor

Is Combination Allowed?

Supervisor A

Supervisor A

Yes

Supervisor B

Supervisor B

Yes

Supervisor A+

Supervisor A+

Yes

Supervisor B+

Supervisor B+

Yes

Supervisor modules are automatically powered up and started with the switch.

To understand the terms that are used for the supervisors, see this table.

Module Terms

Usage

Description

module-27 and module-28

Fixed

  • Module-27 refers to the supervisor module in chassis slot 27 (labeled as SUP 1 on the chassis).

  • Module-28 refers to the supervisor module in chassis slot 28 (labeled as SUP 2 on the chassis).

sup-1 and sup-2

Fixed

  • sup-1 refers to the supervisor module in the SUP 1 slot (slot 27 in the CLI output).

  • sup-2 refers to the supervisor module in the SUP 2 slot (slot 28 in the CLI output.

sup-active and sup-standby

Relative

  • sup-active refers to the active supervisor module—relative to the slot that contains the active supervisor module.

  • sup-standby refers to the standby supervisor module—relative to the slot that contains the standby supervisor module.

sup-local and sup-remote

Relative

If you are logged into the active supervisor, this applies:

  • sup-local refers to the active supervisor module.

  • sup-remote refers to the standby supervisor module.

If you are logged into the standby supervisor, this applies:

  • sup-local refers to the standby supervisor module (the one that you are logged into).

  • There is no sup-remote available from the standby supervisor module (you cannot access a file system on the active supervisor).

Overview of Power Modes

Configure the power modes to either use (redundancy mode for when there is a power loss, or the combined power that is provided by the installed power supply units (no power redundancy):

n+1 redundancy mode

This mode allocates one power supply as a reserve power supply in case an available power supply fails. The remaining power supplies are allocated for available power. The reserve power supply must be at least as powerful as each power supply used for the available power. Use the ps-redundant command to activate this mode.

For example, if a switch requires 2.0 kW of available power and the switch has three power supplies that each output 3 kW, then one of the power supplies provides 3.0 kW of available power and one power supply provides 3.0 kW of reserve power, in case a power supply fails.

n+n redundancy mode

This mode insures load sharing, but the budget becomes half the total PSU capacity. Use a different power source for the active and reserve power sources, so that if the power source that is used for active power fails, the reserve power supply can provide power for the switch. To activate this mode, use the insrc-redundant command.

For example, if the switch requires 4.0 kW of power, the switch has four power supplies that each output 3 kW. If you have two power grids, you use both grid A and grid B to power four 3-kW power supplies that provide the available power for the switch.

Combined mode

This mode allocates the combined power of all power supplies to active power for switch operations. This mode does not allocate reserve power for power redundancy in case of power outages or power supply failures. This mode is not recommended for production.

The amounts of available and reserve power depend on the power redundancy mode that you specify. The amounts of available and reserve power also depends on the number of power supplies that are installed in the switch. For each redundancy mode, consider:

n+1 redundancy mode

The power supply that outputs the most power provides the reserve power so that it can take over for any other power supply that fails. All the other installed power supplies provide the available power. You activate this power mode by using the power redundancy-mode ps-redundant command.

For example, if the power requirement for a switch is 5.2 kW and the switch has two 3.0-kW power supplies outputting 3.0 kW each, consider these power planning scenarios:

  • Scenario 1—No added power supplies

    One 3-kW power supply provides the reserve power and the other 3-kW power supply, also outputting 3.0 kW, provides the available power. The available power (3.0 kW) does not meet the switch requirements of 5.2 kW, so the switch powers up, except for some of its line cards.

  • Scenario 2—Adding one 3-kW power supply

    One 3-kW power supply, which outputs 3.0 kW, provides the reserve power and the other two 3-kW power supplies, also outputting 3.0 kW each, provide enough power (6.0 kW) to meet the switch requirements (5.2 kW), so the entire switch powers up.

The table shows the results for each scenario.

Scenario Power Requirement Output (kW) for Power Supplies Available Power Reserve Power Result
1 2 3

1

5.2 kW

3.0 kW

3.0 kW

—

3.0 kW

3.0 kW

Available power is less than the power requirement for the switch. You cannot power the entire switch (some of the line cards will not power up).

2

5.2 kW

3.0 kW

3.0 kW

3.0 kW

6.0 kW

3.0 kW

Available power exceeds the power requirement for the switch, so the entire switch powers up.

For grid redundancy mode, the power supplies must be divided into two equal sets and installed as:

  • Slots PS 1 to PS 5 must be connected to one grid (Grid A)

  • Slots PS 6 to PS 10 must be connected to another grid (Grid B)

n+n redundancy mode

Half of the 3-kW power supplies are connected to one power source (grid) and the other half are connected to another power source. The available power is provided by one power source and the reserve power is provided by the other power source. If the power source that provides the available power fails, the switch uses the reserve power source to provide its required power. To activate this power mode, use the power redundancy-mode insrc_redundant command.

For example, if the power requirement for a switch is 5.2 kW and the switch has two power supplies that output 3 kW, consider these power planning scenarios:

  • Scenario 1—No added power supplies

    The available power is 3.0 kW (output from one 3-kW power supply) and the reserve power is 3.0 kW (output from the other power supply). The available power (3.0 kW) does not meet the switch requirements (5.2 kW), so most of the modules power up, but some of the line cards will not power up.

  • Scenario 2—Adding two 3-kW power supplies

    The available power is 6.0 kW (output from two 3-kW power supplies on grid A) and the reserve power is 6.0 kW (output from the other two power supplies on grid B). The available power (6.0 kW) exceeds the power requirement of the switch (5.2 kW), so the entire switch powers up.

The table shows the results for each scenario.

Scenario Power Requirement Output for Power Supplies Available Power Reserve Power Result
1 2 3 4

1

5.2 kW

3.0 kW

3.0 kW

—

—

3.0 kW

3.0 kW

Available power (3.0 kW) is less than the power requirement for the switch (5.2 kW)—switch powers up, but some of the line cards cannot power up.

2

5.2 kW

3.0 kW

3.0 kW

3.0 kW

3.0 kW

6.0 kW

6.0 kW

Available power (6.0 kW) exceeds the power requirement for the switch (5.2 kW)—the entire switch powers up.

Combined mode

The Total Power Capacity equals the combined output of all installed power supplies. There is no reserve power. To activate this mode, use the power redundancy-mode combined command. If the Total Power Allocated (budget) for a switch is 5.2 kW and the switch has one 3-kW power supply with 220-V input and 3.0-kW output, consider these power planning scenarios:

  • Scenario 1—No added power supplies

    If you do not add a power supply unit, the available power (3.0 kW) is insufficient for the switch power requirement of 5.2 kW. The switch powers the supervisor modules, system controllers, fan trays, and at least one fabric module before powering as many of the fabric and line cards as the remaining available power can support (one or more fabric or line cards might not be powered).

  • Scenario 2—Install an extra 3-kW power supply

    If you install an extra 3-kW power supply unit that can output 3.0 kW, the available power becomes 6.0 kW. The increased amount of available power exceeds the switch power requirement of 5.2 kW, so all the modules and fan trays in the switch power up.

The table shows the results for each scenario.

Scenario Power Requirement Power Supply 1 Output Power Supply 2 Output Available Power Reserve Power Result

1

5.2 kW

3.0 kW

—

3.0 kW

—

Available power is less than the power requirement for the switch. You cannot power the entire switch. Some of the line cards will not power up.

2

5.2 kW

3.0 kW

3.0 kW

6.0 kW

—

Available power exceeds the power requirement for the switch, so the entire switch powers up.

Setting the Power Mode

To configure the power supply mode, use the power redundancy-mode command.


Note

To display the current power supply configuration, use the show environment power command.

Before you begin

For grid redundancy mode, divide and install the power supplies into two equal sets.

  • Slots PS 1 to PS 5 must be connected to one grid (Grid A).

  • Slots PS 6 to PS 10 must be connected to another grid (Grid B).

Procedure

Step 1

Use the configure terminal command to enter the global configuration mode.

Example:

switch# configure terminal
switch(config)#

Step 2

Use the power redundancy-mode mode command to specify one of these power modes:

  • For combined mode, include the combined keyword.

  • For n+1 redundancy mode, include the ps-redundant keyword.

  • For n+n redundancy mode, include the insrc-redundant keyword.

Example:

switch(config)# power redundancy-mode insrc-redundant
switch(config)#

Overview of Fan Trays

Fan trays provide airflow through the switch for cooling. Each fan tray contains multiple fans to provide redundancy. The switch can continue functioning in these situations:

  • One or more fans fail within a fan tray—Even with multiple fan failures, the switch can continue functioning. When a fan fails within a tray, the functioning fans in the module increase their speed to compensate for the failed fans.

  • The fan tray is removed for replacement—The fan tray is removed and replaced while the switch is operating without presenting an electrical hazard or damage to the switch. The switch can operate for three minutes without the fan tray that you are replacing, but if the switch air-inlet temperature is less than 86 degrees Fahrenheit (30 degrees Celsius), you have up to 72 hours to replace the fan tray. Because temperatures can change over time, we recommend that you replace the fan tray within three minutes.

  • If you remove more than one fan tray at a time, the switch can operate up to three minutes before shutting down. To prevent a shutdown, remove only one fan tray at a time.


Note

When a fan fails or when you remove a fan tray, the remaining operating fans speed up to compensate for the loss of fans. This process can increase the noise that is made by the fan trays until you replace the missing fan tray or replace the defective fan tray.


Note

When replacing a failed fan tray in a running system, be sure to replace the fan tray promptly.


Tip

If one or more fans fail within a fan tray, the Fan Status LED turns red. A fan failure could lead to temperature alarms if not corrected immediately.

The software is continuously monitoring the fan status. In a fan failure, these actions occur:

  • System messages are displayed.

  • Call Home alerts are sent (if configured).

  • SNMP notifications are sent (if configured).

To display the fan module statuses, see Displaying the Status for the Fan Trays.


Note

The fan trays fill slots FAN 1, FAN 2, and FAN 3 in the chassis.

Displaying the Status for the Fan Trays

To display the status of the fan trays, use the show environment fan command.


Note

If the status is not reported for a fan tray and the status LED is not lit for that installed fan tray, check to be sure that there is a fabric module that is installed behind the fan tray. There must be a functioning fabric module installed behind that fan tray for the fan tray to power up.