7.4 Operation management of stack

<Structure of this section>

(1) Configuration

(a) Configuration of the member switch

In a stack, all member switches that make up the stack operate in the same configuration. Each member switch has a startup configuration and a running configuration, but the stack operates with the running configuration set to the same state on all member switches.

(b) Editing the running configuration

The running configuration in a stack configuration can be edited only by the master switch. Only the master switch can edit the running configuration. The running configuration edited on the master switch is synchronized with the running configuration of the other member switches. In addition, when save command is executed on the master switch, the running configuration of all member switches is saved in each startup configuration.

(c) Flow of synchronization with the member switch started later

If the member switch is started later during stack operation, check whether the startup configuration of the member switch started later in the running configuration of the master switch is the same.

When the configuration is the same

The member switches that were launched later remain part of the stack.

When the configuration is different

Use the procedure shown in the following figure to match the configuration and make the member switches part of the stack.

Figure 7-3: Flow up to matching configuration

A mismatch occurs when the running configuration of the master switch is compared with the startup configuration of the member switch started later.
The member switch copies the running configuration of the master switch to the startup configuration and restarts it.
Because the running configuration of the master switch matches the startup configuration of the restarted member switch, the member switch operates in a running configuration synchronized with the running configuration of the master switch.

(2) Execution of operation commands

In the stack, you can use operation commands from the master switch to view and manipulate member switch information. For details about the operation commands in a stack configuration, see [Stack Configuration Operations] in the Operation Command Reference. You can also use the operation command remote command to execute operation commands on a specified member switch from the master switch.

Note the following when executing remote command command:

Operational commands cannot be executed for other member switches in a member switch other than the master switch.
Remote command commandcan be executed on a member switch that has completed initialization. Cannot be executed for a member switch that is being initialized. If this happens, re-execute the command after initialization is completed.
To execute operation commands including remote command command consecutively, execute the following operation commands after remote command command terminates and the command is prompted. If an operation command including a remote command command is entered and executed by copying and pasting, the operation command after remote command command may not be executed. If this happens, re-enter the operation command that was not executed.

(3) User account

In a stack, user accounts on member switches other than the master switch are synchronized to user accounts on the master switch. Therefore, user accounts that exist only on member switches other than the master switch are deleted when you configure the stack. Files under the home directory are not synchronized.

(4) Logging into the Member Switch

In a stack, you can use the operational command session or connect a console to log in to each member switch.

You can identify which member switches are logged in at the command prompt. For example, if you set OFFICE1 in the configuration command hostname and switch number 1 is the master switch and switch number 2 is the backup switch, the command prompt is as follows:

Master switch command prompt: OFFICE1>
Backup switch command prompt: OFFICE1-02B>

The hyphen after the backup switch command prompt indicates the switch number (two characters) and the switch status (one character).

Note that you can log in to a member switch that you have started later only after the master switch and the member switch that you have started are connected. If you cannot log in to a member switch that was started later, use the operation command show switch to check the status of the member switch, or wait until the command prompt for login is displayed.

To log in from a remote operation terminal, log in to the master switch.

If there is no key entry for a certain period of time while connecting with the operation command session, the system will automatically log out, terminate the connection, and return to the switch from which the connection was originally made.

(5) Host key pair of SSH servers

The host key pair of SSH server on a member switch other than the master switch is synchronized with the host key pair of SSH server on the master switch. In addition, when the host key pair is generated and deleted by executing an operation command set ssh hostkey or erase ssh hostkey on the master switch, the host key pair of the member switch other than the master switch is also generated and deleted.

(6) Member switch time

The time of a member switch other than the master switch is synchronized with the time of the master switch. However, since the time is synchronized in seconds, errors may occur between member switches.

When an operation command set clock is executed on the master switch, the time of other member switches is synchronized up to one minute later.

(7) Software management

(a) Software Update

When updating software, update one member switch after updating the port and then update the other member switch. It is recommended to update the backup switch and the master switch in this order.

Use the operation-command show switch to confirm the completion of the update. If the member switch that was updated has been initialized, the update is complete. Also, use the operation-command show port to check that the port is up.

(b) Software and Optional Licenses

It is recommended that you restart the backup switch and then the master switch after configuring the software and option licenses.

If the time between the backup switch restart and the master switch restart takes longer, the stack may not be configured.

(8) Backup and restore of operational information

The backup and restore target includes information called individual member switch stack information files.

(9) Screen output and log saving of operation messages

Event information generated by a member switch is displayed as an operation message on the operation terminal of each member switch, and is also stored in the operation log on each member switch.

Of these, the message type ERR and EVT operational messages are also notified to the master switch. In other words, the operation messages of all member switches are displayed on the operation terminal of the master switch and saved in the master switch as an operation log. Operational messages can also be sent to networked servers using syslog interfaces.

The format of the operation message includes the switch number and the switch status. This allows you to distinguish between the member switches in which the event occurred and their states.

(10) MIB and SNMP Notification

In a stack, SNMP settings can be used to retrieve, configure, and send SNMP notifications MIB in a stand-alone manner.

(11) Advanced scripts

(a) Installing Script Files

When the script file is installed by the operation command install script on the master switch, it is automatically installed on member switches other than the master switch.

To synchronize all installed script files, specify sync parameter in the operation command install script. In this case, all script files installed on a member switch other than the master switch are synchronized to the script file on the master switch. Note that script files that exist only on member switches other than the master switch are deleted.

(b) Starting Scripts

The script can be started on the master switch. The following table describes the script operation when the switch state changes during execution.

Table 7-4: Script operations for switch state transitions
Script type	Transition to master	Transition to backup
Command script	Scripts are not executed automatically.	Scripts that were being executed are forcibly terminated.
Resident script	Start a new resident script.
Event startup script	Starts when a new event is detected on the master switch.

(c) Synchronizing script files

If you have added or replaced a member switch, synchronize the script file. To synchronize, specify sync parameter in the operation command install scrip after matching the software version. If the operation is not synchronized, when the master switch is switched, scripts that are not installed on the member switch that has become the new master switch will not be started.

You can check whether synchronization is required by executing the operation command install script with diff parameter specified.