To add a swap file:

• open an ssh session (tideway user) and execute the command below:

su

• To choose the final/total/required swap (including files and partitions), modify an execute the command below:
  

required_swap_GiByte=32

• To choose the absolute path of the future swap file, modify an execute the command below:
  

new_swap_file=/mnt/addm/backup
df -h `dirname $new_swap_file`

If possible, don't put the swap file in the datastore partition (to optimize perfs) or /usr/tideway (to avoid saturations). The best is to put it in a partition that contains the logs, the transaction logs or the backup. Use the df output to make sure the swap file you are creating is not causing risks of saturation. 

• Execute the commands below

free --gibi
existing_swap_KiByte=`cat /proc/meminfo | grep "SwapTotal" | awk '{print $2}'`
missing_swap_KiByte=$(($required_swap_GiByte*1024*1024-$existing_swap_KiByte))
if [ "$missing_swap_KiByte" -le 0 ]; then
    echo "You already meet the requirement of $required_swap_GiByte GiByte of swap, no need to add more"    
else
    echo "You don't have enough swap, let's add it"
    echo required_swap_GiByte=$required_swap_GiByte existing_swap_KiByte=$existing_swap_KiByte
    echo "let's  add $missing_swap_KiByte KiBytes of swap in a file"
    dd if=/dev/zero of=$new_swap_file bs=1024 count=$(($missing_swap_KiByte+4))
    /sbin/mkswap $new_swap_file
    /sbin/swapon $new_swap_file
    free --gibi
    echo "$new_swap_file       swap     swap     defaults     0 0"    >>   /etc/fstab
    sudo -u tideway tw_service_control --restart
fi
cat /etc/fstab

It is recommended to carefully review the script output. 

To remove the swap file:

• execute "swapon" to identify the absolute path of the swap file(s)
• modifiy and execute the commands below  

su
swapoff <absolute swap file name>rm -f <absolute swap file name>

• edit /etc/fstab
• remove the line(s) about the swap file(s)

Alternative method to creates a 8gb swap file on an existing partition named "/mnt/addm/xxxxxx" .

• Determine the best partition on which to add the swap space. To do this, enter:
  df -h
• Become root user
  su - root
• Check the current swap allocation:
  free -m
• Create an 8gb swap file named /mnt/addm/xxxxxx/swapfile. Change the file name and size(count) as needed. To calculate the "count" :  Xgig * 1048576 = count. For example: