Hot-Swapping Modules In A Stack - Alcatel-Lucent OmniSwitch 6850E Series Hardware User's Manual

Managing OmniSwitch 6850E Series Stacks

Hot-Swapping Modules In a Stack

Modules within a virtual chassis are hot-swappable. NI modules are essentially those modules operating in
the stack in idle mode. These modules can be removed from, or added to, an existing stack without
disrupting other modules in the stack.
Removing Switches from an Existing Stack
When removing switches from an existing stack, observe the following important guidelines:
• Do not attempt to hot-swap modules operating in primary or secondary management roles
• Be sure the stacking cables and stacking cable redundancy are not disrupted
Hot-swapping is intended for switches in idle and, if applicable, pass-through status only. Removing
primary or secondary management modules from a stack will trigger a failover sequence, i.e., one or more
additional modules within the stack must reload in order to reassign the management roles. Whenever
possible, avoid removing a switch that is operating as a primary or secondary management module.
Also, removing a switch from a stacked configuration can disrupt stack cabling at the rear of the stack.
When removing a module, be sure that stacking link integrity, including important stacking cable redun-
dancy, is maintained between all remaining modules. For more information on stacking cable connec-
tions, refer to page 6-17.
Inserting Switches Into an Existing Stack
When inserting switches into an existing stack, observe the following important guidelines:
• Avoid duplicate saved slot numbers
• Never attempt to operate more than eight switches in a single stack
• Make sure all switches are running the same software version.
To avoid duplicate slot numbers, simply make sure that any modules being added to an existing stack have
been cleared of preassigned slot information. In other words, verify that there is no boot.slot.cfg file
present in the /flash directory of any switch being added. When the switch is connected to the existing
stack and booted, the system software automatically assigns it a unique slot number. No duplicate slot
errors occur.
Note. If it is preferable to add a switch with an existing boot.slot.cfg file to a stack, be sure that the saved
slot number of the incoming switch is not already assigned to a switch operating in the stack.
OmniSwitch 6850E Series Hardware Users Guide
January 2013
Hot-Swapping Modules In a Stack
page 6-25