Instead of Windows, I suppose it work on Linux system too? Any specific steps?
Do I disable nginx, mariadb, memcached services.
Install virtualbox and import the virtual image and start it that’s all??
Do I need to do any special configuration in the setting to bind the virtual image IP or leave it as default and it should work??
As I understood, you would like to run ERPNext on Ubuntu server, right? If yes, follow below steps:
Step1 : Configure a Ubuntu VMs minimum 1GB RAM. (You may opt for Digital ocean, Amazon, Google cloud)
Step 2: Update your vm
sudo apt-get update
Step3: Run install script as user
wget https://raw.githubusercontent.com/frappe/bench/master/install_scripts/setup_frappe.sh
sudo bash setup_frappe.sh --setup-production
Step4: Done. Celebrate your brand new ERP 
Note: Your administrator password will be displayed once installation complete.
Sunil
Actually I already have v3 installed but from my experience, the system broken if I do updates occasionally (bad script?). Since it is production, it maybe better to use VM so I can export out as appliance to do major update. If it fail, I can roll back.
bench update break system occasionally, agree with you. Still, I would suggest to use install script to on live server for production.
Including mine, I’m sure there are 100s of ERPNext instance is running on production, live. 
Sunil
Not a bad idea. The latest scripts take a db backup before update also, so you can restore from that too.