Reference Guide

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:
• If one of the new stacks receives the master and standby units, it is unaffected by the split.
• If one of the new stacks receives only the master unit, the master switch retains its role and a new
standby is elected.
• If one of the new stacks receives only the standby unit, it becomes the master in the new stack and
Dell Networking OS elects a new standby.
• If one of the new stacks does not receive either the master or the standby unit, the stack is reset so
that a new election takes place.
Managing Redundant Stack Management
To manage the redundancy behavior in a stack, use the following redundancy commands.
• Reset the current stack master and make the standby unit the new master.
EXEC Privilege mode
redundancy force-failover stack-unit
Stacking
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