A few questions regarding AWSEC2-CloneInstanceAndUpgradeWindows

So my main question on this is what exactly happens after the upgrade. Is the original VM just automatically replaced or do I need to manually point my public IP to the converted instance? The documentation isn't clear on this.

Edited by: motohead400 on Jul 19, 2021 6:14 AM

Hi there, hope you are doing well!

I see that you would like to understand how the document ‘AWSEC2-CloneInstanceAndUpgradeWindows’ operates. Please find your queries addressed below.

The document ‘AWSEC2-CloneInstanceAndUpgradeWindows’ basically creates an Image (AMI) of your instance -> launches a temporary instance with it -> performs upgrade on the temporary instance -> Creates an image from the temporary instance after upgrade for you to use [1]. Now to answer your queries,

1. “First, I'm running SQL Server Express locally on my Ec2 instance. I assume I need to stop any sites using it while the upgrade is going on so that there's no data loss due to the upgrade?”
   • While running the document, you may choose the NoReboot option. This will tell the document execution not to reboot the instance during the first image creation process.
   • However, when you get the final upgraded image. You will need to launch a new instance with that image, which will serve as a replacement to the original instance. For this, you will need to switch the application to the new instance which will cause some downtime. Thus, I would recommend that you schedule the switching over to the new instance accordingly.
2. “I assume the new instance will retain the same IP address just like before?”
   • The document will generate an image (with upgraded OS) as the output. You will need to create the new instance manually using the image.
   • If you want the new instance to have the same private IP as the existing one, you will need to first terminate the original instance so that you can use its private IP on the new instance.
   • If your existing instance has an Elastic IP attached, you can detach the Elastic IP and attach to the new instance.
3. “Will the newly upgraded instance start on its own automatically? Basically is there any additional steps I need to perform after the upgrade has finished?”
   • No. The upgraded instance will need to be launched automatically using the AMI generated by the document.
4. “Is the original VM just automatically replaced or do I need to manually point my public IP to the converted instance?”
   • The original instance remains untouched and you will manually need to create the upgraded instance from the image.
   • You will also need to detach the public Elastic IP from the existing/original instance and associate it with the new instance.

I hope I was able to address your queries to the fullest.

Have a great day!

Reference:
[1] https://docs.aws.amazon.com/systems-manager-automation-runbooks/latest/userguide/automation-awsec2-CloneInstanceAndUpgradeWindows.html

Thank you that's exactly what I needed to know.