Swap out MX 250 Warm spare vs cold swap

[hmc25000]

I need to swap out our 250 MX because of an issue with the current one crashing. 

Reading the documentation I'm inclined to assume that configuring a warm spare might be easier and have less downtime than doing a cold swap. 

Can anyone with experience recommend what the best way is with the least amount of downtime. 

[MerakiDave]

Hi @hmc25000 this also came up in another recent thread below.  Check here https://documentation.meraki.com/MX/Other_Topics/MX_Cold_Swap_Replacing_an_Existing_MX_with_a_Differ...

In particular look over the section "Adding a Second MX to Form a Warm Spare Configuration" which seems most relevant and is going to minimize your actual downtime if you've got a tight outage window.

Hope that helps.

[hmc25000]

Thanks.

I'm a little confused with method 1 from the document. If I understand it correctly the Method 1 can be done 

"Adding the Replacement MX to the Same Network" or "Adding a Second MX to Form a Warm Spare Configuration".

I understand for both you have to remove the old MX prior to adding the new one. How can you add a warm spare if you have removed the old MX? Can I assume there will be no downtime when I add the new as a warm spare and than remove the old MX? I just want o make sure I understand it correctly.