I have been working on making a swap file because every time I use the terminal to use the following option:
java -Xmx2G -Xms1G -jar server.jar
to start the server, it crashes. I have tried multiple different options for how much ram I should allocate but every time it crashes.
When I use the following command
sudo mkswap /swapfile
To check if it's enabled or not, I get an error saying:
swapon: /swapfile: swapon failed: Device or resource busy
Does anybody know a fix to this?
I am only 14 so if you can sum up your text any easier to make it more understandable that would be very nice of you

How much physical memory is installed in the computer?
sudo swapon -s should show if swap is enabled as well as a non zero number from the output of the command free.

You probably need to specify more ram if you got it. Min is 2GB but with mods I think you need more. I don't think adding more swap is going to help.

This is the memory total:
4007992
this is how much is being used:
3439564
do you know how much ram that is?
thank you for your response
I will try the sudo swapon -s command

That is basically 4GB. Total used also includes buffers a cache so that does not look out of the ordinary.
What other min,max options have you tried? Have you tried Xms2G Xmx2G or Xms2G Xmx2.5G?
I'm thinking with mods you might not have enough memory.

I tried XMx 4G and XMs 2G and added 2G each time from there. I'll try what you said. I Only put 1 mod in the a folder for the server, its this mod
https://reforged.gg/
I got the one for 1.20.2 that's the only mod I put in though

Xmx 2G and XMx 2G worked! Thank you very much! I resolved the problem