AWS has soft support limit for 40 attached EBS devices. Assuming there is just
one root device, use the rest for persistent volumes.

The devices will have name /dev/xvdba - /dev/xvdcm, leaving /dev/sda - /dev/sdz
to the system.

Also, add better error handling and propagate error
"Too many EBS volumes attached to node XYZ" to a pod.