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This chapter describes how to configure high availability, and describes the switchover processes.
Process restartability provides the high availability functionality in Cisco MDS 9000 Series switches. This process ensures that process-level failures do not cause system-level failures. It also restarts the failed processes automatically. This process is able to restore its state prior to the failure and continues executing from the failure point going forward.
An HA switchover has the following characteristics:
Note | Switchover is not allowed if auto-copy is in progress. |
Switchovers occur by one of the following two processes:
Once a switchover process has started another switchover process cannot be started on the same switch until a stable standby supervisor module is available.
Caution | If the standby supervisor module is not in a stable state (ha-standby), a switchover is not performed. |
The running image is automatically synchronized in the standby supervisor module by the active supervisor module. The boot variables are synchronized during this process.
The standby supervisor module automatically synchronizes its image with the running image on the active supervisor module.
Note | The image a supervisor module is booted up from cannot be deleted from bootflash. This is to ensure that the new standby supervisor module ia able to synchronize during the process. |
Be aware of the following guidelines when performing a manual switchover:
To manually initiate a switchover from an active supervisor module to a standby supervisor module, use the system switchover command. After you enter this command, another switchover process cannot be started on the same switch until a stable standby supervisor module is available.
To ensure that an HA switchover is possible, enter 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, then the switchover is possible. See Verifying Switchover Possibilities for more information.
This section describes how to verify the status of the switch and the modules before a manual switchover.
switch# show module
Mod Ports Module-Type Model Status
--- ----- ------------------------------- ------------------ ------------
2 8 IP Storage Services Module DS-X9308-SMIP ok
5 0 Supervisor/Fabric-1 DS-X9530-SF1-K9 active *
6 0 Supervisor/Fabric-1 DS-X9530-SF1-K9 ha-standby
8 0 Caching Services Module DS-X9560-SMAP ok
9 32 1/2 Gbps FC Module DS-X9032 ok
Mod MAC-Address(es) Serial-Num
--- -------------------------------------- ----------
2 00-05-30-00-9d-d2 to 00-05-30-00-9d-de JAB064605a2
5 00-05-30-00-64-be to 00-05-30-00-64-c2 JAB06350B1R
6 00-d0-97-38-b3-f9 to 00-d0-97-38-b3-fd JAB06350B1R
8 00-05-30-01-37-7a to 00-05-30-01-37-fe JAB072705ja
9 00-05-30-00-2d-e2 to 00-05-30-00-2d-e6 JAB06280ae9
* 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. If the status is either OK or active, you can continue with your configuration.
switch# show boot auto-copy
Auto-copy feature is enabled
switch# show boot auto-copy list
No file currently being auto-copied
Note | This functionality is disabled by default. |
To configure internal CRC detection and isolation, perform these steps:
The table below lists the default settings for interface parameters.
Parameters |
Default |
---|---|
Internal CRC Error Handling |
Disabled |
You can copy the boot variable images that are in the active supervisor module (but not in the standby supervisor module) to the standby supervisor module. Only those KICKSTART and SYSTEM boot variables that are set for the standby supervisor module can be copied. For module (line card) images, all boot variables are copied to the corresponding standby locations (bootflash: or slot0:) if not already present.
To enable or disable automatic copying of boot variables, follow these steps:
Use the show boot auto-copy command to verify the current state of the copied boot variables. This example output shows that automatic copying is enabled:
switch# show boot auto-copy Auto-copy feature enabled
This example output shows that automatic copying is disabled:
switch# show boot auto-copy Auto-copy feature disabled
Use the show boot auto-copy list command to verify what files are being copied. This example output displays the image being copied to the standby supervisor module's bootflash. Once this is successful, the next file will be image2.bin.
Note | This command only displays files on the active supervisor module. |
switch# show boot auto-copy list File: /bootflash:/image1.bin Bootvar: kickstart File:/bootflash:/image2.bin Bootvar: system
This example output displays a typical message when the auto-copy option is disabled or if no files are copied:
switch# show boot auto-copy list No file currently being auto-copied
Use the show system redundancy status command to view the HA status of the system. Tables Redundancy States to Internal States Table 1 and Table 3 explain the possible output values for the redundancy, supervisor, and internal states.
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:
The following table lists the possible values for the 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 is ready to be configured. |
||
Standby |
A switchover is possible. |
||
Failed |
The switch detects a supervisor module failure on initialization and automatically attempts to power-cycle the module three (3) 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 switch has established connection with the supervisor and the supervisor module is performing diagnostics. |
||
Unknown |
The switch is in an invalid state. If it persists, call TAC. |
The following table lists the possible values for the supervisor module states.
State |
Description |
---|---|
Active |
The active supervisor module in the switch is ready to be configured. |
HA standby |
A switchover is possible. |
Offline |
The switch is intentionally shut down for debugging purposes. |
Unknown |
The switch is in an invalid state and requires a support call to TAC. |
The following table lists the possible values for the internal redundancy states.
State |
Description |
---|---|
HA standby |
The HA switchover mechanism in the standby supervisor module is enabled (see the Synchronizing Supervisor Modules section). |
Active with no standby |
A switchover is not possible. |
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 switch is being shut down. |
HA switchover in progress |
The switch is in the process of changing over to the HA switchover mechanism. |
Offline |
The switch 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 is present but is not functioning. |
Other |
The switch is in a transient state. If it persists, call TAC. |
The system uptime refers to the time that the chassis was powered on and has at least one supervisor module controlling the switch. Use the reset command to reinitialize the system uptime. Nondisruptive upgrades and switchovers do not reinitialize the system uptime, which means that the system uptime is contiguous across such upgrades and switchovers.
The kernel uptime refers to the time since the NX-OS software was loaded on the supervisor module. Use the reset and reload commands to reinitialize the kernel uptime.
The active supervisor uptime refers to the time since the NX-OS software was loaded on the active supervisor module. The active supervisor uptime can be lower than the kernel uptime after nondisruptive switchovers.
You can use the show system uptime command to view the start time of the system, uptime of the kernel, and the active supervisor.
This example shows how to display the supervisor uptime:
switch# show system uptime System start time: Fri Aug 27 09:00:02 2004 System uptime: 1546 days, 2 hours, 59 minutes, 9 seconds Kernel uptime: 117 days, 1 hours, 22 minutes, 40 seconds Active supervisor uptime: 117 days, 0 hours, 30 minutes, 32 seconds
For more information on high availability, see chapter 1, High Availability Overview.