Can not start instance - No root volume attached - After migrating to encrypted volume

Question

I am migrating a Windows instance's unencrypted disk to an encrypted. I have created a snapshot of its volume, made an encrypted copy of the snapshot and created a volume from the encrypted snapshot.

I have detached the old unencrypted volume and attached the new encrypted volume. I can read that the volume is listed in block devices as xvdf. Root device field is empty.

When I start the instance, the following error message is displayed, I am confused with the /dev/sda1 because this in a Windows VM.

Error starting instances Invalid value 'i-c892a644' for instanceId. Instance does not have a volume attached at root (/dev/sda1)

Answer 1

You must attach the encrypted volume under the same name as the original one was, i.e. as /dev/sda1. Don't worry that Windows don't have /dev/sda1 - it's the AWS name for the device.

You'll have to detach the volume from EC2 and re-attach. You will have to manually type /dev/sda1 in the box as the root volume names are usually not found in the drop-down menu.

Looking at one of our Windows instances it indeed does have the root volume attached as /dev/sda1:

Hope that helps :)