Add SWAP on box

[araczkowski]

Normally(after system installation on eMMC) the SWAP memory is not configured on box, so when your programs use more memory then DDR memory on box then LMK (low memory killer) is run and the program is killed.

To be able to run more programs and not be killed by system when memory is low you need to add SWAP memory - allocate memory on disc.

For this you should do (as root):

1. Create a file that will serve as swap memory
   fallocate -l 8G /swapfile
   8G means 8 gigabytes. You can adjust this value, for example, to 2G for 2 GB.

2. Set the correct permissions
   chmod 600 /swapfile

3. Configure the file as swap
   mkswap /swapfile

4. Activate the swap file
   swapon /swapfile

5. Check your swap memory
   free -h

6. Set up persistent activation after reboot (By default, the swap file will not be automatically activated after a system reboot. To fix this, you must add an entry to the /etc/fstab file)
   cp /etc/fstab /etc/fstab.bak
nano /etc/fstab
   Add the following line to the end of the file:
   /swapfile none swap sw 0 0

Now after reboot you will have your swap 🎉

And when your programs will eat more memory then your DDR on box then the SWAP will be used instead of LMK