If the Quick I/O feature is licensed and installed, Quick I/O is enabled by default when a file system is mounted. The -o qio and -o noqio mount options enable and disable, respectively, Quick I/O when a file system is mounted.

If Quick I/O is not installed or licensed, a file system mounts by default without Quick I/O and no error message is displayed. However, if you specify the -o qio option, the mount command prints the following error message and terminates without mounting the file system.

  VxFDD: You don't have a license to run this program
  vxfs mount: Quick I/O not available