Reference Guide

Split an S-Series 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
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 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.
Stack Unit and Stack Group Numbering
Enable ports for stacking by specifying a stack-unit number and stack-group number (the stack-unit
number stack-group number command).
• Stack-unit numbers: By default, each switch in Standalone mode is numbered stack-unit 0. Stack-
unit numbers are assigned to member switches when a stack comes up. To pre-configure the units
which are the master and standby when the stack boots up, you can assign unit numbers using the
stack-unit renumber command.
• Stack-group numbers: Stacking ports are divided into 16 stack-groups (from 0 to 15), as shown in the
following illustration. Each set of four 10 GbE ports on an Ethernet module or each fixed 40 GbE port
on the front panel correspond to a stack group. Each stack group has 40 GbE of bandwidth.
Usage Notes:
• Stacking is not supported on Fibre Channel ports.
• If you use a Fibre Channel module in an S5000 switch, stacking is not supported on Ethernet ports.
• If you use three or more S5000 units in a stack, you can connect up to a maximum of eight 10 GbE
ports or two 40 GbE ports in links between peer switches.
• If you use only two S5000 units in a stack, you can connect up to four 40 GbE ports in links between
the two switches.
Stack groups 0 through 11 consist of four 10 GbE ports; stack groups from 12 to 15 consist of one 40G
port as follows:
Stack Group Ports
0 0 to 3
1 4 to 7
2 8 to 11
3 12 to 15
4 16 to 19
5 20 to 23
910
Stacking