// 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
		if totalSize > 0 {
			remaining := totalSize - written
			if remaining < int64(len(buf)) {
				buf = buf[:remaining]
			}

	xlStorageFormatFile = "xl.meta"

	// XL metadata file backup file carries previous per object metadata.
	xlStorageFormatFileBackup = "xl.meta.bkp"
)

var alignedBuf []byte

func init() {
	alignedBuf = disk.AlignedBlock(xioutil.DirectioAlignSize)
	_, _ = rand.Read(alignedBuf)
}

// isValidVolname verifies a volname name in accordance with object
// layer requirements.
func isValidVolname(volname string) bool {