Dell PowerConnect FCS624S Configuration Guide - Page 200

5 More about IronStack technology If secure-setup times out (this may happen due to inactivity), you will not be able to make any changes in your configuration or stack topology until you restart the session by entering the stack secure-setup command. The unit discovery process is triggered when secure-setup is initiated. However, if the stack unit is placed in a topology where another unit in the stack is already running the discovery process, the current discovery process is terminated. If this is the case, you will see a message similar to the following. "Topology discovery is already in progress originated from . Please try later." This means a discovery process is already active and was initiated from the unit with the mentioned in the message. You will need to re-issue secure-setup. If there is already an active discovery process, secure-setup may not discover all the intended units. If this is the case, you will need to restart the secure-setup process. Troubleshooting unit replacement issues If you are unsuccessful in building a stack using the automatic setup process (refer to "Scenario 2 Configuring a three-member IronStack in a ring topology using the automatic setup process" on page 105), or adding or replacing a unit in a stack, consider the following issues: • Make sure that the number of units in your stack does not exceed the maximum of 8 • Make sure that the replacement unit is a clean unit (does not contain a startup-config.txt file) • Make sure that the replacement unit running configuration does not contain "stack enable" • Make sure the replacement unit running configuration does not contain "stack disable" • Make sure that the configurations of the stack ports on the Active Controller match the physical connections to the unit More about IronStack technology This section discusses stacking technology in greater detail than the information presented in Section 1. Configuration, startup configuration files and stacking flash Stacking system behavior is defined by the run time configuration, which can be displayed using the show run command. The write memory command stores the run time configuration in a flash file called startup-config.txt. During bootup, the system reads and applies the startup-config.txt file to the run time configuration. The startup-config.txt file can be shown using the show config command. The stacking system installs a stacking.boot file on each unit that tells the unit what its role is during the boot process. The stacking.boot file is generated whenever there is an election that defines the roles for all units. When an Active Controller is booted, or a write memory command is issued, the Active Controller synchronizes its startup-config.txt file to every stack unit. The original startup-config.txt files in the Standby Controller and other stack members are renamed to startup-config.old. If you issue the "stack unconfigure me" command on the Standby Controller or stack member directly, these units 158 PowerConnect B-Series FCX Configuration Guide 53-1002266-01