delete_cleanup_interval         (duration)  set to change intervals when deleted objects are permanently deleted from ".trash" folder (default: '5m')
odirect                         (boolean)   set to enable or disable O_DIRECT for writes under special conditions. NOTE: do not disable O_DIRECT without prior testing (default: 'on')
root_access                     (boolean)   turn 'off' root credential access for all API calls including s3, admin operations (default: 'on')

}

// checkODirectDiskSupport asks the disk to write some data
// with O_DIRECT support, return an error if any and return
// errUnsupportedDisk if there is no O_DIRECT support
func (s *xlStorage) checkODirectDiskSupport(fsType string) error {
	if !disk.ODirectPlatform {
		return errUnsupportedDisk
	}

	// We know XFS already supports O_DIRECT no need to check.
	if fsType == "XFS" {
		return nil
	}

**In our tests we also found ext4 does not honor POSIX O_DIRECT/Fdatasync semantics, ext4 trades performance for consistency guarantees. Please avoid ext4 in your setup.**