Settings Root Device on EC2

Question

I would like to change the "Root Device" for an EC2 EBS backed instance using the AWS Console.

"sda1" was set as the root device but I detached the EBS volume and mounted it elsewhere to fix a boot error, and when I re-attached it to the original instance as /dev/sda the root device is still shown as blank in the AWS console.

Any idea?

Answer 1

Scratch that, the problem was I was attaching as /dev/sda (which is the normal way to attach an EBS volume) but actually for the root device it needed to be an explicit partition, i.e. /dev/sda1