No connection to Google Compute engine instance after upgrading on advice google team

Question

I resize instance from 4 cpu to 2, after this, server not responded, SSH connection timeout to instance.

I cannot understand why this problem occurred, and how to solve it. Thanks a lot.

Answer 1

I suppose that you've followed documentation Changing the Machine Type of a Stopped Instance and after that your VM instance is running, but you're not able to connect via Cloud console web interface and via Cloud Shell with a command gcloud compute ssh.

Please restart your VM instance, if it's possible, and check logs at Compute Engine -> VM instances -> click on NAME_OF_YOUR_VM -> at the VM instance details find section Logs and click on Serial port 1 (console) for any error or warning messages that could explain what happened to your VM instance.

After that, please have a look at the documentation Troubleshooting SSH and follow the instructions. You'll be able to choose appropriate action after checking console log at the previous step.

Also, you can connect to your VM via Serial console by following this guide, but keep in mind that:

The interactive serial console does not support IP-based access restrictions such as IP whitelists. If you enable the interactive serial console on an instance, clients can attempt to connect to that instance from any IP address.

more details you can find in the documentation.

If nothing helped, please add full console log to your question by using hastebin.com or other similar service and describe which steps you've done so far by following Troubleshooting SSH guide.