I have tried with a single stack cable and both stack cables (2-1, 1-2 and 1-1, 2-2), reloading each time. Dell Pro Support says the way the cables are connected does not matter; they link up anyway. But won't stack!

Hi, thanks for choosing Dell. 

https://dell.to/3kWArji

https://dell.to/3L6oAK2

page 224

I hope these are helpful. Let us know if you have any further questions.

My switches are N3048, not N3048-ON -- does that manual apply to mine?

For what it's worth, I did set the Unit number (via the console) for the switch I want to join as a stack member from 1 to 6 to make sure there isn't a conflict (even though they should sort that out themselves, I wanted to do everything I could to make sure the intended master switch is indeed the master switch in the stack).

Then, on the intended master switch (Unit 1), I preconfigured a stack member so it is expecting an N3048 switch with the unit number 6 to be present. (e.g., console(config-stack)#member 4 6)
("show switch" shows that this expected switch is "Not Present")

I've power cycled / reloaded the switches many times and they always come up as lone master / mgmt switches with no stack members either way.

From the RAM log:

Hi, If the stacking cable works fine, Can you check below steps again please for avoid overlooked any steps?

Stacking on N30xx Series Switches

If you are using Dell Networking OS 6.3(0.16), you can stack up to 12 switches using the mini-SAS ports located on the rear of the switch.
N30xx switches only support stacking with other N30xx switches. When you connect multiple switches together through the stack ports,
they operate as a single unit with up to 576 I/O-side ports. The stack operates and is managed as a single entity.
NOTE: If you are installing a stack of switches, assemble and cable the stack before powering up and configuring it. When you
power-up a stack for the first time, the switches elect a Master switch, which may occupy any location in the stack. The Master
LED on the I/O-side lights on the master unit.
Creating a Switch Stack
Create a stack by connecting adjacent units using the mini-SAS stacking ports on the PSU-side of the switch. Figure 20 shows the
switches connected in a ring topology. A ring topology is the recommended topology for a stack..
1 Connect one of the mini-SAS cables into either of the stacking ports of the top switch and the switch directly below it.
If necessary, use a separately purchased, longer (1–meter or 3–meter) mini-SAS cable to connect the switches.
2 Repeat this process until all the devices are connected.
3 Use the remaining stacking cable to connect the two remaining stacking ports together to create a ring topology.
36 N30xx Series Installation

Figure 23. N30xx Stack in a Ring Topology
1 N30xx stack
2 Mini-SAS cables attached in a ring topology
The ring topology stack has the following physical connections between the switches:
• The bottom mini-SAS port on Unit 1 is connected to the top mini-SAS port on Unit 2.
• The bottom mini-SAS port on Unit 2 is connected to the top mini-SAS port on Unit 3.
• The bottom mini-SAS port on Unit 3 is connected to the top mini-SAS port on Unit 1.
Stacking Standby on Dell Networking OS 6.3(0.16)
The stacking feature on Dell Networking OS version 6.3(0.16) supports a Standby or backup unit that assumes the Master unit role if the
Master unit in the stack fails. As soon as a Master failure is detected in the stack, the Standby unit initializes the control plane and enables
all other stack units with the current configuration. The Standby unit maintains a synchronized copy of the running configuration for the
stack. The Standby unit is automatically selected in the stack; however, you can use the CLI to select a different stack member as
Standby. For more information, see the User's Configuration Guide or the CLI Reference Guide

refer pg26 https://dell.to/3N4i2gv

Thank you for the reply, Erman.

"Stack Master LED and Stack Number Display
When a switch within a stack is the master unit, the Stack Master LED is solid green. If the Stack Master LED is off, the stack member is not the master unit. The Stack No. panel displays the unit number for the stack member. If a switch is not part of a stack (in other words, it is a stack of one switch), the Stack Master LED is illuminated and the unit number is displayed."

The Stack Master LED is illuminated on both switches confirming as I mentioned above that they are essentially two separate "stacks" of a single switch each. And even though I only have 2 switches for this stack, I have tried with and without the ring topology (1-bottom to 2-top, 2-bottom to 1-top) cabling.

I have not omitted any steps, but the directions above refer to v6.3(.0.16) but we're running v6.2.6.6. This is the firmware version on the production switch, so I did upgrade the recent switch we purchased (used) from an earlier firmware to match 6.2.6.6.

I have even seen screenshots from similar stacks where the stack member shows "code mismatch" because the firmware does not match. I can't even get this switch to join the stack and show up at all. I can log into either switch's console and manage them independently, but the point and purpose of buying this switch is to create a stack to extend the existing switch.

Hello paulson,

It seems you have already covered the things we have provided on the forum.

Have you followed up with your support case owner?  They can do remote session with you to get a look.

We've done two remote sessions so far. I was hoping someone here would have magic knowledge.

Are there any additional logs or debugging logs to enable or view that may shed light on why they fail to stack?

If we upgrade the firmware on these two switches to something more recent, might that introduce compatibility problems with communicating with other N3048 switches (left on their current firmware) in our environment that are not part of this stack?

Unfortunately, I'm not aware of any additional debugging logs to check it.