Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{
			Key:         apiODirect,
			Description: "set to enable or disable O_DIRECT for writes under special conditions. NOTE: do not disable O_DIRECT without prior testing" + defaultHelpPostfix(apiODirect),
			Optional:    true,
			Type:        "boolean",
		},
		config.HelpKV{
			Key:         apiRootAccess,

// errInconsistentDisk - inconsistent disk found.
var errInconsistentDisk = StorageErr("inconsistent drive found")

// errUnsupporteDisk - when disk does not support O_DIRECT flag.
var errUnsupportedDisk = StorageErr("drive does not support O_DIRECT")

// errDiskFull - cannot create volume or files when disk is full.
var errDiskFull = StorageErr("drive path full")

// errDiskNotDir - cannot use storage disk if its not a directory

// used with DIRECT I/O based file descriptor and it is expected that
// input writer *os.File not a generic io.Writer. Make sure to have
// the file opened for writes with syscall.O_DIRECT flag.
func CopyAligned(w io.Writer, r io.Reader, alignedBuf []byte, totalSize int64, file *os.File) (int64, error) {
	if totalSize == 0 {
		return 0, nil
	}

	var written int64
	for {
		buf := alignedBuf

}

// 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
	}

   $ minio server /data-{1...4}/minio # Single Node Multi Drive`,
	)

	ErrUnsupportedBackend = newErrFn(
		"Unable to write to the backend",
		"Please ensure your drive supports O_DIRECT",
		"",
	)

	ErrUnableToWriteInBackend = newErrFn(
		"Unable to write to the backend",
		"Please ensure MinIO binary has write permissions for the backend",

		var hint string
		if endpoint.URL != nil {
			hint = fmt.Sprintf("Drive '%s' does not support O_DIRECT flags, MinIO erasure coding requires filesystems with O_DIRECT support", endpoint.Path)
		} else {
			hint = "Drives do not support O_DIRECT flags, MinIO erasure coding requires filesystems with O_DIRECT support"
		}
		logger.Fatal(config.ErrUnsupportedBackend(err).Hint(hint), "Unable to initialize backend")

**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.**

	OTPSELECT                        = 0x80044d0d
	O_APPEND                         = 0x400
	O_ASYNC                          = 0x2000
	O_CLOEXEC                        = 0x80000
	O_CREAT                          = 0x40
	O_DIRECT                         = 0x4000
	O_DIRECTORY                      = 0x10000
	O_DSYNC                          = 0x1000
	O_EXCL                           = 0x80
	O_FSYNC                          = 0x101000

	OTPSELECT                        = 0x80044d0d
	O_APPEND                         = 0x400
	O_ASYNC                          = 0x2000
	O_CLOEXEC                        = 0x80000
	O_CREAT                          = 0x40
	O_DIRECT                         = 0x10000
	O_DIRECTORY                      = 0x4000
	O_DSYNC                          = 0x1000
	O_EXCL                           = 0x80
	O_FSYNC                          = 0x101000

	OTPSELECT                        = 0x80044d0d
	O_APPEND                         = 0x400
	O_ASYNC                          = 0x2000
	O_CLOEXEC                        = 0x80000
	O_CREAT                          = 0x40
	O_DIRECT                         = 0x4000
	O_DIRECTORY                      = 0x10000
	O_DSYNC                          = 0x1000
	O_EXCL                           = 0x80
	O_FSYNC                          = 0x101000