Reference Guide

The new unit synchronizes its running and startup configurations with the stack.
To add a standalone switch which has stack groups already configured to a stack, use the next steps.
7. Attach port cables to connect the ports in pre-configured stack groups to one or more switches in
the stack.
8. Power on the switch. Dell networking OS automatically assigns a number to the new unit and adds it
as member switch in the stack.
The new unit synchronizes its running and startup configurations with the stack.
Dell Networking OS Behavior: When you add a new switch to a stack:
• When you add a unit to a stack, the management unit performs a system check on the new unit to
ensure the hardware type (S5000) is compatible. The Dell Networking OS version performs a similar
check. If the stack is running 9.1(1.0) and a new unit is running a different software version, the new
unit is put into a card problem state. The new unit is then upgraded to use the same Dell Networking
OS version as the stack and is rebooted before joining the stack.
• If the new unit has been configured with a stack number that is already assigned to a stack member,
the stack avoids a numbering conflict by assigning the new switch the first available stack number.
• After the new unit loads, it synchronizes its running and startup configurations with the stack.
Merging Two Stacks
You can merge two S5000 switch stacks while they are powered and online.
To merge two stacks, connect one stack to the other using port cables. After you connect the port
cables, the two stacks merge:
• Dell networking OS selects a master switch for the merged stack from the existing masters in the two
stacks.
To ensure that one of the two master switches wins the master election in the merged stack, use the
stack-unit priority command to configure the highest priority for the unit (refer to Assigning a Priority
to Stacked Switches).
• All the units in the losing stack reboot and then merge with the winning stack that has the stack
master.
• If there is no unit numbering conflict, the stack members retain their previous unit numbers.
Otherwise, the stack master assigns new unit numbers, based on the order in which they come
online.
• The new stack master uses its own startup and running configurations to synchronize the
configurations on the new stack members.
NOTE: Adding a new unit that is powered on and has stack groups configured is the same as
merging two stacks (refer to Adding a Stack Unit). If the new unit is configured with a higher priority
than the current stack master, it becomes the new stack master and the stack reloads. If the new
unit does not have a higher priority than the master switch, it reboots and is added as a member
switch.
Split a Stack
To split an S5000 stack, unplug the port cables between member units at any time: while the stack is
powered on or off and when the units are online or offline.
Each portion of the split stack retains the startup and running configuration of the original stack.
For a stack that is split into two smaller stacks, each with multiple units:
Stacking
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