Replacement of an M8024-K stack member....

I think it would save some time by manually updating the switch to the correct firmware, before adding it to the stack. If you are planning on some downtime, you could update the master unit to the latest firmware too.

5.1.9.4

http://dell.to/1UunA4G

The configuration will sync from the master to the backup, no reboot is required for the sync to occur. This means that if you plan to update the master switch, you can plan for 1 stack reboot. If you update the replacement switch to the same revision as the master, no reboot is needed.

Here is a white paper that covers stacking the switches. It includes some information on removing and adding stack members. Good info to have.

http://dell.to/1QVWiEJ

Hope this helps.

To enable synchronization, run the following commands on the master switch.

# boot auto-copy-sw

# boot auto-copy-sw allow-downgrade

We would like to minimize downtime, so we'd like to keep the current Master up and running for as long as possible during this process.   We'd like to follow the route where the Master causes an automatic  upgrade/downgrade of the firmware on the new card being introduced.

Great, thanks....   So, when the switch is inserted, it will have the firmware upgraded/downgraded.  (then just the new switch will reboot)?    after the firmware is equal, then the configuration will sync, and the new switch will be brought into the stack.  At this point, does the entire STACK reboot, or just the new member?

The Master switch should not need a reboot during the synchronization process. However, i would still do this during non peak hours, in case something unexpected occurs and the switch does need to reboot.

Daniel, thanks for the guidance!   ---Let me re-state  my facts in one spot, and let me know if I have it straight....----Here's what I think will happen....

We will need the two commands in place to allow for config-sync, and for downgrade of firmware:

# boot auto-copy-sw

# boot auto-copy-sw allow-downgrade

FACT:  The existing master already has all the stacking-commands in place from before the 2nd member failed

We insert the switch, and:

1.) The switch boots, and the Master Switch will initiate an updgrade or downgrade of the firmware on the replacement switch

2.) the new replacement switch reboots after the firmware upgrade/downgrade.

3.) when the new switch comes up, it will receive the config from the Master

4.) At this point, the new replacement switch should a.)have the proper firmware  and  b.)have a sync'ed config from the master.  

5.) If we issue, "show switch", we should see both switches present, with one indicating, "Mgmt Sw" and one indicting "Stack Mbr"

--do I have it straight?  ---just so we know what to expect.....

Ensure that the proper steps are following when adding the new switch to the stack.

-install new switch into chassis.

-Power up new switch

-set interfaces to stack mode

-power off switch

-cable stack connections

-power up replacement switch

Upon boot, the replacement switch will sync firmware with the master switch. Once the sync is done, the replacement switch will then reboot. After the reboot finishes you will be able to see the replacement switch in the stack.

so its necessary to change one single config item on the New Replacement Switch:  setting two interfaces into stack-mode, and nothing else.    When the new Replacement Switch boots the second time,  the Master's config will overwrite what's on the new switch?

That is correct, no other config changes should be needed on the replacement switch.

Yes, you are absolutely correct. You will need to save the running config to startup config.

Daniel,  what about the switch operating mode?  new/replacement kit ships in simple mode, if in place stack is in normal mode, would you have to update the configuration to normal mode for the new/replacement to join the stack?

Daniel,  what about the switch operating mode?  new/replacement kit ships in simple mode, if in place stack is in normal mode, would you not have to change this on the config of the new/replacement?

Each scenario in the stacking white paper assumes that the switch is in Normal Mode (not Simple Mode) and using firmware version 4.2.x.x or later. If Simple Mode is enabled it will need to be disabled prior to stacking the switches.

http://dell.to/1QVWiEJ

To change to normal mode, simply run the following command.

console(config)#mode simple

Cheers

Thanks Daniel.  Found the reference on page 7.