Administrator Guide

Merge Two Stacks
You may merge two stacks while they are powered and online.
To merge two stacks, connect one stack to the other using the mini-SAS cables from the stacking ports.
• Dell EMC Networking OS selects a master stack manager from the two existing managers based on the priority of the stack.
• Dell EMC Networking OS resets all the units in the losing stack; they all become stack members.
• If there is no unit numbering conflict, the stack members retain their previous unit numbers. Otherwise, the stack manager assigns
new unit numbers, based on the order that they come online.
• The stack manager overwrites the startup and running config on the losing stack members with its own to synchronize the
configuration on the new stack members.
Split a Stack
To split a stack, unplug the desired stacking cables.
You may do this at any time, whether the stack is powered or unpowered, and the units are online or offline. Each portion of the split stack
retains the startup and running configuration of the original stack.
For a parent stack that is split into two child stacks, A and B, each with multiple units:
• If one of the new stacks receives the master and the standby management units, it is unaffected by the split.
• If one of the new stacks receives only the master unit, that unit remains the stack manager, and Dell EMC Networking OS elects a
new standby management unit.
• If one of the new stacks receives only the standby unit, it becomes the master unit of the new stack, and Dell EMC Networking OS
elects a new standby unit.
• If one of the new stacks receives neither the master nor the standby management unit, the stack is reset so that a new election can
take place.
Stacking Configuration Tasks
Following are the stacking configuration tasks:
• Assigning Unit Numbers to Units in a Stack
• Creating a Virtual Stack Unit in a Stack
• Displaying Information About a Stack
• Influencing Management Unit Selection on a Stack
• Managing Redundancy on a Stack
• Resetting a Unit on a Stack
• Recover from Stack Link Flaps
Assigning Unit Numbers to Units in an Stack
Each unit in the stack has a stack number that is either assigned by you or Dell EMC Networking OS.
Units are numbered from 1 to 12. Stack numbers are stored in NVRAM and are preserved upon reload.
• Assign a stack-number to a unit.
EXEC Privilege mode
stack-unit old-unit-number renumber new-unit-number
Renumbering the stack manager triggers the whole stack to reload, as shown in the message below. When the stack comes back online,
the master unit remains the management unit.
Dell#stack-unit 2 renumber 1
Renumbering master unit will reload the stack.
WARNING: Interface configuration for current unit will be lost!
Proceed to renumber [confirm yes/no]: yes
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Stacking