ssh not working and server inaccessible (server down)

Solution 1:

so from yesterday to today, I can not access server in browser or via SSH. Server down / offline.

How to solve a suddenly problematic server like this?

Apart from having regular ssh, you should have console access to google cloud platform. (Console access is a sort of emergency/maintenance backdoor ) .If you don't have access to google cloud platform, ask for the person who created the vm for you.

if the vm is down start it,

 1. Go to the Google Cloud Platform Console. Open the console left side
 2. menu and select Compute Engine. On the left, select VM Instances.
 3. Select the checkboxes next to the instances that you want to start,
    and then click the Start button.

more. https://cloud.google.com/billing/docs/how-to/restart-services

console access etc https://cloud.google.com/compute/docs/instances/connecting-to-instance

Support Options https://cloud.google.com/support/

Solution 2:

You could use the serial console, this would need to be enabled.

Edit the VM:

Remote access Enable connecting to serial ports

https://cloud.google.com/compute/docs/instances/interacting-with-serial-console?hl=en_US