Shuttoff or shutdown

Official Hardware Classic Yún
1

Hi,

my question concerning the correct "turn off" procedure for Yun:
Can you just shutoff the power or does Linux needs a proper shutdown, especially when you have installed further packages?

Thanks!!!

2

I just unplug the Yun and have seen no ill effects, the only thing I have noticed is things in /tmp go away so don't use the temp directory to store stuff you want to keep.

More importantly, I have seen nothing in the documentation or forum. I expect the Arduino Yun people would have prominent warnings if a "proper" shutdown was needed.

3

Thank You!!!!!

4

noblepepper:
More importantly, I have seen nothing in the documentation or forum. I expect the Arduino Yun people would have prominent warnings if a "proper" shutdown was needed.

Indeed there is nothing particular to do, just unplug it. That said, if you customize the yun running whatever program needs a proper shutdown, you need to shut that program down properly and only then unplug the yun

5

The Raspberry Pi forums will tell you that you shouldn't just unplug, you should shut down first. I think this is especially relevant if the linux computer is busy writing to the SD card. I don't see why that wouldn't also apply to the Linux side of the Yun. You can connect a button to the Arduino that can then programmatically call the linux shutdown command, sudo shutdown -h now. Then you'd still have to wait for that to finish – I think indicating it with an LED somehow would be ideal.

6

The Yún runs a version of Linux called OpenWrt, which doesn't have a shutdown command. There's also no "sudo" command since you are always logged in as root.

There is a reboot command, but no shutdown. Being Linux it's not a good idea to simply turn off the power suddenly, especially if you've expanded its filesystem onto an SD card. You can actually — like any Linux OS — damage the filesystem by turning off the power without a proper shutdown.

So absent a shutdown command, how to shut down the Yún?

It turns out there is a halt command, which if you don't include a "-n" argument will also sync (synchronise) the filesystem prior to the halt.

So apparently the safe way is to shut down the Yún is with this:

  root@yun:~# halt

Note that if you're in a terminal and type 'halt' your terminal will freeze. This is normal; your Yún has disconnected the ssh session and halted. Now you can either power down or push the "YUN RST" button to reset/reboot the processor.