@sdetweil Just thinking might be confusing to someone if they forgot that command, went hunting for it, saw pm2 start mm then don’t know why it won’t start.
First installation I did was the “official” manual installation.
That actually bit me on my second installation which used your installation script. I had the manual installation pm2 start mm set in my head from manual installation. I figured it out pretty promptly but I still like to skim through those first few sections to make sure I didn’t miss/forget a step.

Doing new MM installation and noticed on page that tell you how to setup and use pm2 it references pm2 start mm.

You might want to edit page to reflect the current pm2 start MagicMirror. If you use @sdetweil automated installation.

@sdetweil This a follow-on question regarding developer tools while MM running. If you have a module that is updating at a rapid pace it gets to be a real challenge trying to drill down to the lines you want to look at because at each cycle it will close all the expanded subsections. Is there a way to stop that other than setting a large update value?
Seems like it was either stock ticker or news ticker were culprits as rest of modules like calendar you can update every 12 hours or so.

@sdetweil When you address header as in the question above are you not speaking to the page as a whole?
Some modules have headers effectively turned on while others have header turned off.
I know that it pays to look at how each individual module is configured by its author.
If author of module in question is setting that property in their module CSS which one will take precedence, the
header { property}
or
.mymodule {property}

The following is from my big screen nightmare project via @Piranha1605 and is for setting border color but I think would be applicable to other module properties as well.

.module.MMM-CalendarExt2,
.module.weather,
.module.currentweather,
.module.calendar,
.module.MMM-Pollen,
.module.MMM-SystemStats {
 background-color:#2a313b;
 border-radius:8px;
 padding:8px;
 box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 1), 0 8px 20px 0 rgba(0, 0, 0, 0.19);
}

@matt216 Maybe some version of
.module.mymodule .header { yada yada }

.mymodule .header { yada yada }

SWAG on my part in some respects.

@djboob66 I have a portable Toshiba drive plugged in to the very Pi I want to make the copy of. Originally bought to upload camera images from my camera’s SD card. Plugged in a few months ago to see how the Pi would respond.

@sdetweil Thanks. Seems easy enough. There seem to be more than one way to skin that cat. Which is preferred?

Can I copy the whole SD card of an existing MM + Raspian OS on to a second SD card. I have a spare Pi and a donor monitor but not so proficient in Linux based commands and my copying experience more at the file/folder level.

@sdetweil That wa the ticket. Ran npm install on that module, said it installed 2 components which I took as a positive sign. Un-commented the module in config.js and running well.

So I did a direct copy paste of MMM-NewsFeedTicker from a MM where it works flawlessly over to big screen MM where it doesn’t work flawlessly.

If I comment out the NewsFeedTicker in config.js everything is good. Put back in service and it just pops up a black screen that I assume is some alternative terminal, Electron.
The only difference is that the MM that works is running older version of MM as I have not updated it.