I'm trying to
- create an EBS volume
- create an EC2 instance, and then
- attach the volume to the instance.
But when I try this, I keep hitting InsufficientInstanceCapacity. Apparently, there's still lots of room for EBS volumes in certain zones, but no more EC2 instances can be created.
Is there an easy way to test for this condition, so that I can hide zones with no capacity from the user? Or is there some other trick, such as creating an EBS volume without specifying an availability zone, that will allow me to pick a zone with leftover capacity without guessing randomly?