Overcloud deployment failing because director/ironic is trying to create a partion larger the then disk

Issue

• When using VMs in a PoC/test installation, the deployment of the overcloud is failing because the director is not correctly partitioning the hard drive of the target node.
• The deployment has a problem with the root disk.

• Should I use Gigabytes (GB) or Gigibytes (GiB) when provisioning storage?

  2016-07-13 07:51:04.329 1525 ERROR ironic.drivers.modules.deploy_utils [-] StdErr: u'Warning: The resulting partition is not properly aligned for best performance.\nError: The location 40962 is outside of the device /dev/sdb.\n'