System-Level High Availability

This chapter describes the Cisco NX-OS high availability (HA) system and application restart operations and includes the following sections:

About Cisco NX-OS System-Level High Availability

Cisco NX-OS system-level HA mitigates the impact of hardware or software failures and is supported by the following features:

Physical Redundancy

The Cisco Nexus 9504, 9508, and 9516 chassis include the following physical redundancies:

  • Power supply

  • Fan tray

  • Switch fabric

  • System controller

  • Supervisor module

The Cisco Nexus 9300 platform switches include the following physical redundancies:

  • Power supply

  • Fan tray

For additional details about physical redundancies, see the Hardware Installation Guide for your specific Cisco Nexus 9000 Series chassis.

Power Supply Redundancy

The Cisco Nexus 9504 chassis supports up to four power supply modules, the Cisco Nexus 9508 chassis supports up to eight power supply modules, and the Cisco Nexus 9516 chassis supports up to ten power supply modules. Each 9500 platform power supply module can deliver up to 3 kW.

The power subsystem allows the power supplies to be configured in one of the available redundancy modes. By installing more modules, you can ensure that the failure of one module does not disrupt system operations. You can replace the failed module while the system is operating. For information on power supply module installation and replacement, see the Hardware Installation Guide for your specific Cisco Nexus 9000 Series chassis.

Power Modes

Each of the power redundancy modes imposes different power budgeting and allocation models, which deliver varying usable power yields and capacities. For more information about power budgeting, usable capacity, planning requirements, and redundancy configuration, see the Hardware Installation Guide for your specific Cisco Nexus 9000 Series chassis.

The available power supply redundancy modes are described in the following table.

Table 1. Power Redundancy Modes

Redundancy Mode

Description

Combined (nonredundant)

This mode does not provide power redundancy. The available power is the total power capacity of all power supplies.

insrc-redundant (grid redundancy)

This mode provides grid redundancy when you connect half of the power supplies to one grid and the other half of the power supplies to the second grid. The available power is the amount of power available through a grid.

To enable grid redundancy, you must connect the power supplies to the correct power grid slots. For example, on the Cisco Nexus 9508 switch, slots 1, 2, 3, and 4 are in grid A, and slots 5, 6, 7, and 8 are in grid B. To configure and operate in grid redundancy mode, you must connect half of your power supplies to the slots in grid A and the rest of your power supplies to the slots in grid B. For more information on power grid slot assignments for your power supplies, see the Hardware Installation Guide for your specific Cisco Nexus 9000 Series platform.

ps-redundant (N+1 redundancy)

This mode provides an extra power supply if an active power supply goes down. One power supply of all the available power supplies is considered an extra power supply, and the total available power is the amount provided by the active power supply units.

Use the power redundancy-mode {combined | insrc_redundant | ps-redundant} command to specify one of these power modes.

Fan Tray Redundancy

The Cisco Nexus 9000 Series switches contain redundant system fan trays for cooling the system. For the number of supported fan trays per chassis, see Physical Redundancy.

The fan speeds are variable and depend on the temperature of the ASICs in the system. If fans are removed or go bad, the other fan modules can start running at a higher speed to compensate for the missing or failed fans. If the system temperature increases above the thresholds, the system shuts down.

  • If a single fan fails within a fan tray, the fan speed of the other fans in the tray does not increase.

  • If multiple fans fail within a fan tray, the fan speed increases to 100% on all the fan trays.

  • If an entire fan tray is removed, the fan speed for the other two fan trays increases to 100% as soon as the tray is removed.

  • If multiple fan trays are removed and not replaced within 2 minutes, the device will shut down. The switch can be recovered by power cycle. When the device comes back, if it still detects the multiple fan tray failure, it will shut down again after 2 minutes. If required, you can use EEM to overwrite this policy.

  • If a fan tray fails, leave the failed unit in place to ensure proper airflow until you can replace it. The fan trays are hot swappable, but you must replace one fan tray at a time. Otherwise, the device reboots after 2 minutes if multiple fan trays are missing.


Note

There is no time limit for replacing a single fan tray, but to ensure proper airflow, replace the fan tray as soon as possible.

Switch Fabric Redundancy

Cisco NX-OS provides switching fabric availability through redundant switch fabric module implementation. You can configure a single Cisco Nexus 9504, 9508, or 9516 chassis with one to six switch fabric modules for capacity and redundancy. Each line card installed in the system automatically connects to and uses all functionally of the installed switch fabric modules. A failure of a switch fabric module triggers an automatic reallocation and balancing of traffic across the remaining active switch fabric modules. Replacing the failed fabric module reverses this process. After you insert the replacement fabric module and bring it online, traffic is again redistributed across all installed fabric modules and redundancy is restored.

Fabric modules are hot swappable. Hot swapping can temporarily disrupt traffic. To prevent the disruption of traffic when you hot-swap fabric modules, use the poweroff module slot-number command before you remove a fabric module and the no poweroff module slot-number command after you reinsert the fabric module.

X9400 line cards: To achieve the maximum bandwidth allowed per card requires four fabric modules (N9K-C95xx-FM-S for the N9K-X9432C-S or N9K-C95xx-FM for the other X9400 line cards) in four fabric module slots (FM2, FM3, FM4, and FM6). Additional fabric modules will not provide additional redundancy for these line cards.

X9500 line cards: To achieve the maximum bandwidth allowed per card requires three fabric modules (N9K-C95xx-FM) in the even fabric module slots (FM2, FM4, and FM6). Additional fabric modules will provide additional redundancy for these line cards. Each even fabric module provides redundancy for each odd fabric module failure (FM2 provides redundancy for FM1, FM4 provides redundancy for FM3, and FM6 provides redundancy for FM5).

X9600 line cards: The maximum bandwidth allowed per card requires six fabric modules (N9K-C95xx-FM).

X9600-R line cards: The maximum bandwidth allowed per N9K-X9636C-R requires five fabric modules (N9K-C95xx-FM-R), and the maximum bandwidth allowed per N9K-X9636Q-R requires four fabric modules (N9K-C95xx-FM-R). Additional fabric modules will provide additional redundancy for these line cards. The maximum bandwidth allowed per N9K-X96136YC-R line card requires six N9K-C9504-FM-R fabric modules for redundancy. The maximum bandwidth allowed per N9K-X9636C-R (P-100) requires 5 fabric modules. The maximum bandwidth allowed per N9K-X9636-RX requires 6 fabric modules for redundancy.

X9700-EX line cards: The maximum bandwidth allowed per card requires four fabric modules (N9K-C95xx-FM-E) in four fabric module slots (FM2, FM3, FM4, and FM6). Additional fabric modules will not provide additional redundancy for these line cards.

X9700-FX line cards: The maximum bandwidth allowed per N9K-X9788TC-FX requires 2 fabric modules. N9K-X9732C-FX requires 4 fabric modules (N9K-C9508-FM-E2 and N9K-C9516-FM-E2) for maximum bandwidth. N9K-X9732C-FX is redundant with 5 fabric modules (the fabric modules can be either 95xx-FM-E or 95xx-FM-E2). N9K-X9736C-FX requires 5 fabric modules for maximum bandwidth. N9K-X9736C-FX is not redundant with additional fabric modules (the fabric modules can be either 95xx-FM-E or 95xx-FM-E2). Fabric Module 25 is the fifth fabric module for both N9K-X9732C-FX and N9K-X9736C-FX. FM25 will be powered down if there are any EX linecards in the chassis.


Note

To achieve Fabric module redundancy, N9k-9732C-FX should not be mixed with any older modules. If any other module is detected, Fabric Module 25 is powered down by the system.


Line card and Fabric module failures

To keep line cards and Fabric module powered down whenever they fail or crash, use the system module failure-action shutdown command to prevent the cards from rebooting. This command is useful if your topology is configured for network-level redundancy and you want to prevent a second disruption from occurring in the network because a line card or fabric module is trying to come up.

You can use the show module module command to verify that the line card has been powered down. If desired, use the no poweroff module module command to manually bring the module (fabric or line card) back up.

switch(config)# system module failure-action shutdown
2014 Sep 8 23:31:51 switch %$ VDC-1 %$ %SYSMGR-SLOT1-2-SERVICE_CRASHED:
Service "ipfib" (PID 2558) hasn't caught signal 11 (core will be saved).

2014 Sep 8 23:32:25 switch %$ VDC-1 %$ %PLATFORM-2-MOD_PWRDN:
Module 1 powered down (Serial number SAL1815Q1DP)

switch(config)# show module 1
Mod  Ports  Module-Type                           Model            Status
---  -----  ------------------------------------- --------------- ----------
1    52     48x1/10G-T 4x40G Ethernet Module      N9K-X9564TX     powered-dn

switch(config)# no poweroff module 1
2014 Sep 8 23:34:31 switch %$ VDC-1 %$ %PLATFORM-2-PFM_MODULE_POWER_ON:
Manual power-on of Module 1 from Command Line Interface

2014 Sep 8 23:34:31 switch %$ VDC-1 %$ %PLATFORM-2-MOD_DETECT:
Module 1 detected (Serial number SAL1815Q1DP) Module-Type 48x1/10G-T 
4x40G Ethernet Module Model N9K-X9564TX

2014 Sep 8 23:34:31 switch %$ VDC-1 %$ %PLATFORM-2-MOD_PWRUP:
Module 1 powered up (Serial number SAL1815Q1DP)

System Controller Redundancy

Two redundant system controllers in the Cisco Nexus 9504, 9508, and 9516 chassis offload chassis management functions from the supervisor modules. The controllers are responsible for managing power supplies and fan trays and act as a central point for the Gigabit Ethernet Out-of-Band Channel (EOBC) between the supervisors, fabric modules, and line cards.

Supervisor Module Redundancy

The Cisco Nexus 9504, 9508, and 9516 chassis support dual supervisor modules to provide 1+1 redundancy for the control and management plane. A dual supervisor configuration operates in an active or standby capacity in which only one of the supervisor modules is active at any given time, while the other acts as a standby backup. The state and configuration remain constantly synchronized between the two supervisor modules to provide stateful switchover in the event of a supervisor module failure.

A Cisco NX-OS generic online diagnostics (GOLD) subsystem and additional monitoring processes on the supervisor trigger a stateful failover to the redundant supervisor when the processes detect unrecoverable critical failures, service restartability errors, kernel errors, or hardware failures.

If a supervisor-level unrecoverable failure occurs, the currently active failed supervisor triggers a switchover. The standby supervisor becomes the new active supervisor and uses the synchronized state and configuration while the failed supervisor is reloaded. If the failed supervisor is able to reload and pass self-diagnostics, it initializes, becomes the new standby supervisor, and then synchronizes its operating state with the newly active unit.

Supervisor Modules

Two supervisor modules are available for the Cisco Nexus 9000 Series switches: Supervisor A (SUP A) and Supervisor B (SUP B). The following table lists the differences between the two modules.

Supervisor A

Supervisor B

Supervisor A+

Supervisor B+

CPU

4 core, 1.8 GHz

6 core, 2.1 GHz

4 core, 1.8 GHz

6 core, 1.9 GHz

Memory

16 GB

24 GB

16 GB

32 GB

SSD storage

64 GB

256 GB

256 GB

256 GB

Software release

6.1(2)I1(1) or later release

6.1(2)I3(1) or later release

7.0(3)I7(1)

7.0(3)I7(1)

SUP A and SUP B are not compatible and should not be installed in the same chassis, except for migration purposes. For dual supervisor systems, you should install either two SUP A modules or two SUP B modules (and not a combination of the two) to ensure supervisor module redundancy.

In a dual supervisor system, Cisco NX-OS checks the memory size of both the active and standby supervisors. If the memory size is different for each supervisor (because both SUP A and SUP B are installed), a message appears instructing you to replace SUP A with a second SUP B.

To migrate from SUP A to SUP B, insert SUP B into the device and enter the system switchover command. SUP B becomes the active supervisor, and SUP A becomes the standby supervisor, which is not a supported configuration. A warning message appears every hour until you remove SUP A or replace it with a second SUP B.

Supervisor Restarts and Switchovers

Restarts on Single Supervisors

In a system with only one supervisor, when all HA policies have been unsuccessful in restarting a service, the supervisor restarts. The supervisor and all services reset and start with no prior state information.

Restarts on Dual Supervisors

When a supervisor-level failure occurs in a system with dual supervisors, the System Manager performs a switchover rather than a restart to maintain stateful operation. In some cases, however, a switchover might not be possible at the time of the failure. For example, if the standby supervisor module is not in a stable standby state, a restart rather than a switchover is performed.

Switchovers on Dual Supervisors

A dual supervisor configuration allows nonstop forwarding (NSF) with a stateful switchover (SSO) when a supervisor-level failure occurs. The two supervisors operate in an active/standby capacity in which only one of the supervisor modules is active at any given time, while the other acts as a standby backup. The two supervisors constantly synchronize the state and configuration in order to provide a seamless and stateful switchover of most services if the active supervisor module fails.

Switchover Characteristics

An HA switchover has the following characteristics:

  • It is stateful (nondisruptive) because control traffic is not affected.

  • It does not disrupt data traffic because the switching modules are not affected.

  • Switching modules are not reset.

Switchover Mechanisms

Switchovers occur by one of the following two mechanisms:

  • The active supervisor module fails and the standby supervisor module automatically takes over.

  • You manually initiate a switchover from an active supervisor module to a standby supervisor module.

When a switchover process begins, another switchover process cannot be started on the same switch until a stable standby supervisor module is available.

Switchover Failures

Supervisor switchovers are generally hitless and occur without traffic loss. If for some reason a switchover does not complete successfully, the supervisors reset. A reset prevents loops in the Layer 2 network if the network topology was changed during the switchover. For optimal performance of this recovery function, we recommend that you do not change the Spanning Tree Protocol (STP) default timers.

If three system-initiated switchovers occur within 20 minutes, all nonsupervisor modules shut down to prevent switchover cycling. The supervisors remain operational to allow you to collect system logs before resetting the switch.

Manually Initiating a Switchover

To manually initiate a switchover from an active supervisor module to a standby supervisor module, use the system switchover command. After you run this command, you cannot start another switchover process on the same system until a stable standby supervisor module is available.


Note

If the standby supervisor module is not in a stable state (ha-standby), a manually initiated switchover is not performed.


To ensure that an HA switchover is possible, use the show system redundancy status command or the show module command. If the command output displays the ha-standby state for the standby supervisor module, you can manually initiate a switchover.

Switchover Guidelines

Follow these guidelines when performing a switchover:

  • When you manually initiate a switchover, it takes place immediately.

  • A switchover can be performed only when two supervisor modules are functioning in the switch.

  • The modules in the chassis must be functioning.

Verifying Switchover Possibilities

This section describes how to verify the status of the switch and the modules before a switchover.

  • Use the show system redundancy status command to ensure that the system is ready to accept a switchover.

  • Use the show module command to verify the status (and presence) of a module at any time. A sample output of the show module command follows:

    switch# show module
    Mod  Ports  Module-Type                           Model            Status
    ---  -----  ------------------------------------- ---------------- ----------
    1    32     32p 40G Ethernet Module               N9K-X9432PQ      ok
    2    52     48x1/10G SFP+ 4x40G Ethernet Module   N9K-X9564PX      ok
    5    52     48x1/10G SFP+ 4x40G Ethernet Module   N9K-X9464PX      ok
    6    36     36p 40G Ethernet Module               N9K-X9536PQ      ok
    7    36     36p 40G Ethernet Module               N9K-X9536PQ      ok
    10   32     32p 40G Ethernet Module               N9K-X9432PQ      ok
    11   52     48x1/10G-T 4x40G Ethernet Module      N9K-X9564TX      ok
    12   52     48x1/10G-T 4x40G Ethernet Module      N9K-X9464TX      ok
    15   52     48x1/10G SFP+ 4x40G Ethernet Module   N9K-X9464PX      ok
    21   0      Fabric Module                         N9K-C9516-FM     ok
    22   0      Fabric Module                         N9K-C9516-FM     ok
    23   0      Fabric Module                         N9K-C9516-FM     ok
    24   0      Fabric Module                         N9K-C9516-FM     ok
    25   0      Fabric Module                         N9K-C9516-FM     ok
    26   0      Fabric Module                         N9K-C9516-FM     ok
    27   0      Supervisor Module                     N9K-SUP-A        ha-standby
    28   0      Supervisor Module                     N9K-SUP-A        active *
    29   0      System Controller                     N9K-SC-A         active
    30   0      System Controller                     N9K-SC-A         standby
    
    Mod  Sw                Hw     Slot
    ---  ----------------  ------ ----
    1    6.1(2)I3(1)      0.1050 LC1
    2    6.1(2)I3(1)      0.2010 LC2
    5    6.1(2)I3(1)      0.1010 LC5
    6    6.1(2)I3(1)      0.2060 LC6
    7    6.1(2)I3(1)      0.2060 LC7
    10   6.1(2)I3(1)      0.1010 LC10
    11   6.1(2)I3(1)      0.2100 LC11
    12   6.1(2)I3(1)      0.1010 LC12
    15   6.1(2)I3(1)      0.1050 LC15
    21   6.1(2)I3(1)      0.3010 FM1
    22   6.1(2)I3(1)      0.3040 FM2
    23   6.1(2)I3(1)      0.3040 FM3
    24   6.1(2)I3(1)      0.3040 FM4
    25   6.1(2)I3(1)      0.3010 FM5
    26   6.1(2)I3(1)      0.3040 FM6
    27   6.1(2)I3(1)      1.1    SUP1
    28   6.1(2)I3(1)      1.1    SUP2
    29   6.1(2)I3(1)      1.2    SC1
    30   6.1(2)I3(1)      1.2    SC2
    
    Mod  MAC-Address(es)                         Serial-Num
    ---  --------------------------------------  ----------
    1    74-26-ac-10-cb-0c to 74-26-ac-10-cb-9f  SAL1817REX2
    2    00-22-bd-fd-93-57 to 00-22-bd-fd-93-9a  SAL1733B92R
    5    74-26-ac-eb-99-0c to 74-26-ac-eb-99-4f  SAL1814PTNM
    6    c0-8c-60-62-60-98 to c0-8c-60-62-61-2b  SAL1812NTG1
    7    c0-8c-60-62-5f-70 to c0-8c-60-62-60-03  SAL1812NTFD
    10   74-26-ac-e9-32-68 to 74-26-ac-e9-32-fb  SAL1811NH4K
    11   78-da-6e-74-15-14 to 78-da-6e-74-15-57  SAL1746G7XE
    12   74-26-ac-ec-2b-50 to 74-26-ac-ec-2b-93  SAL1816QUQX
    15   c0-8c-60-62-a3-b4 to c0-8c-60-62-a3-f7  SAL1816QGXE
    21   NA                                      SAL1801K507
    22   NA                                      SAL1813P9Y2
    23   NA                                      SAL1813P9YM
    24   NA                                      SAL1813P9Y9
    25   NA                                      SAL1801K50F
    26   NA                                      SAL1813NZN3
    27   c0-67-af-a1-0e-d6 to c0-67-af-a1-0e-e7  SAL1803KWXY
    28   c0-67-af-a1-0d-a4 to c0-67-af-a1-0d-b5  SAL1804L578
    29   NA                                      SAL1801JU2Z
    30   NA                                      SAL1801JU4V
    
    Mod  Online Diag Status
    ---  ------------------
    1    Pass
    2    Pass
    5    Pass
    6    Pass
    7    Pass
    10   Pass
    11   Pass
    12   Pass
    15   Pass
    21   Pass
    22   Pass
    23   Pass
    24   Pass
    25   Pass
    26   Pass
    27   Pass
    28   Pass
    29   Pass
    30   Pass
    
    * this terminal session
    
    

    The Status column in the output should display an OK status for switching modules and an active or ha-standby status for supervisor modules.

  • Use the show boot auto-copy command to verify the configuration of the auto-copy feature and if an auto-copy to the standby supervisor module is in progress. Sample outputs of the show boot auto-copy command are as follows:

    
    switch# show boot auto-copy
    Auto-copy feature is enabled
    
    switch# show boot auto-copy list
    No file currently being auto-copied
    

Replacing the Active Supervisor Module in a Dual Supervisor System

You can nondisruptively replace the active supervisor module in a dual supervisor system.

Procedure

  Command or Action Purpose
Step 1

switch # system switchover

Initiates a manual switchover to the standby supervisor.

Note 

Wait until the switchover completes and the standby supervisor becomes active.

Step 2

switch# reload module slot-number force

Boots the supervisor module replacement immediately.

Note 

If you do not force the boot, the replacement supervisor module should be booted by the active supervisor module 6 minutes after insertion. For information on replacing a supervisor module, see the Hardware Installation Guide for your specific Cisco Nexus 9000 Series chassis.

Step 3

switch# copy bootflash:nx-os-image bootflash:nx-os-image

Copies the nx-os image from the active supervisor module to the standby supervisor module.

Step 4

switch# configure terminal

Enters global configuration mode.

Step 5

switch (config)# boot nxos bootflash:nx-os-image [sup-number]

Configures the standby supervisor boot variables.

Step 6

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

(Optional)

Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration.

Example

This example shows how to replace the active supervisor module in a dual supervisor system:


switch# system switchover
 Raw time read from Hardware Clock: Y=2013 M=2 D=2 07:35:48
 writing reset reason 7,
 
NX9 SUP Ver 3.17.0
Serial Port Parameters from CMOS
PMCON_1: 0x200
PMCON_2: 0x0
PMCON_3: 0x3a
PM1_STS: 0x1
Performing Memory Detection and Testing
Testing 1 DRAM Patterns
Total mem found : 4096 MB
Memory test complete.
NumCpus = 2.
Status 61: PCI DEVICES Enumeration Started
Status 62: PCI DEVICES Enumeration Ended
Status 9F: Dispatching Drivers
Status 9E: IOFPGA Found
Status 9A: Booting From Primary ROM
Status 98: Found Cisco IDE
Status 98: Found Cisco IDE
Status 90: Loading Boot Loader
 Reset Reason Registers: 0x1 0x10
 Filesystem type is ext2fs, partition type 0x83
 Filesystem type is ext2fs, partition type 0x83
 
              GNU GRUB  version 0.97
 
 
                Loader Version 3.17.0

current standby sup
----------------------------
switch(standby)# 2014 Aug  2 07:35:46 switch %$ VDC-1 %$ %KERN-2-SYSTEM_MSG: Switchover started by redundancy driver - kernel
2014 Aug  2 07:35:47 switch %$ VDC-1 %$ %SYSMGR-2-HASWITCHOVER_PRE_START: This supervisor is becoming active (pre-start phase).
2014 Aug  2 07:35:47 switch %$ VDC-1 %$ %SYSMGR-2-HASWITCHOVER_START: This supervisor is becoming active.
2014 Aug  2 07:35:48 switch %$ VDC-1 %$ %SYSMGR-2-SWITCHOVER_OVER: Switchover completed.

switch# reload module 27 force
switch# copy bootflash:n9000-dk9.6.1.2.I3.1.bin bootflash:n9000-dk9.6.1.2.I3.1.bin
switch# config terminal
switch# boot nxos bootflash:n9000-dk9.6.1.2.I3.1.bin sup-1
switch# copy running-config startup-config

Replacing the Standby Supervisor Module in a Dual Supervisor System

You can nondisruptively replace the standby supervisor module in a dual supervisor system.

Procedure

  Command or Action Purpose
Step 1

switch# reload module slot-number force

Boots the supervisor module replacement immediately.

Note 

If you do not force the boot, the replacement supervisor module should be booted by the active supervisor module 6 minutes after insertion. For information on replacing a supervisor module, see the Hardware Installation Guide for your specific Cisco Nexus 9000 Series chassis.

Step 2

switch# copy bootflash:nx-os-image bootflash:nx-os-image

Copies the nx-os image from the active supervisor module to the standby supervisor module.

Step 3

switch# configure terminal

Enters global configuration mode.

Step 4

switch (config)# boot nxos bootflash:nx-os-image [sup-number]

Configures the standby supervisor boot variables.

Step 5

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

(Optional)

Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration.

Example

This example shows how to replace the standby supervisor module in a dual supervisor system:

switch# reload module 27 force
switch# copy bootflash:n9000-dk9.6.1.2.I3.1.bin bootflash:n9000-dk9.6.1.2.I3.1.bin
switch# config terminal
switch# boot nxos bootflash:n9000-dk9.6.1.2.I3.1.bin sup-1
switch# copy running-config startup-config

Displaying HA Status Information

Use the show system redundancy status command to view the HA status of the system.


switch# show system redundancy status
Redundancy mode
---------------
      administrative:   HA
         operational:   HA
This supervisor (sup-1)
-----------------------
    Redundancy state:   Active
    Supervisor state:   Active
      Internal state:   Active with HA standby
Other supervisor (sup-2)
------------------------
    Redundancy state:   Standby
    Supervisor state:   HA standby
      Internal state:   HA standby

The following conditions identify when automatic synchronization is possible:

  • If the internal state of one supervisor module is Active with HA standby and the other supervisor module is ha-standby, the system is operationally HA and can perform automatic synchronization.

  • If the internal state of one of the supervisor modules is none, the system cannot perform automatic synchronization.

The following table lists the possible values for the redundancy states.

Table 2. Redundancy States

State

Description

Not present

The supervisor module is not present or is not plugged into the chassis.

Initializing

The diagnostics have passed, and the configuration is being downloaded.

Active

The active supervisor module and the switch are ready to be configured.

Standby

A switchover is possible.

Failed

The system detects a supervisor module failure on initialization and automatically attempts to power-cycle the module three times. After the third attempt, it continues to display a failed state.

Offline

The supervisor module is intentionally shut down for debugging purposes.

At BIOS

The system has established a connection with the supervisor, and the supervisor module is performing diagnostics.

Unknown

The system is in an invalid state. If it persists, call TAC.

The following table lists the possible values for the supervisor module states.

Table 3. Supervisor States

State

Description

Active

The active supervisor module in the switch is ready to be configured.

HA standby

A switchover is possible.

Offline

The system is intentionally shut down for debugging purposes.

Unknown

The system is in an invalid state and requires a support call to TAC.

The following table lists the possible values for the internal redundancy states.

Table 4. Internal States

State

Description

HA standby

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

Active with no standby

A switchover is impossible.

Active with HA standby

The active supervisor module in the switch is ready to be configured. The standby supervisor module is in the ha-standby state.

Shutting down

The system is being shut down.

HA switchover in progress

The system is in the process of entering the active state.

Offline

The system is intentionally shut down for debugging purposes.

HA synchronization in progress

The standby supervisor module is in the process of synchronizing its state with the active supervisor modules.

Standby (failed)

The standby supervisor module is not functioning.

Active with failed standby

The active supervisor module and the second supervisor module are present, but the second supervisor module is not functioning.

Other

The system is in a transient state. If it persists, call TAC.

Additional References for System-Level High Availability

This section describes additional information related to system-level high availability.