How can an EBS volume which is currently attached to an EC2 instance in one AZ be migrated to another AZ ?
Detach the volume and attach to an EC2 instance in another AZ.
Create a new volume in the other AZ and speciW the current volume as the source.
Create a snapshot of the volume and then create a volume from the snapshot in the other AZ
Create a new volume in the AZ and do a disk copy of contents from one volume to another.