**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.**

				n, err = w.Write(buf[:len(buf)-remain])
				if err != nil {
					return written, err
				}
				nw = int64(n)
			}

			// Disable O_DIRECT on fd's on unaligned buffer
			// perform an amortized Fdatasync(fd) on the fd at
			// the end, this is performed by the caller before
			// closing 'w'.
			if err = disk.DisableDirectIO(file); err != nil {
				return written, err
			}

	flags := os.O_CREATE | os.O_WRONLY | os.O_TRUNC

	var w *os.File
	if sync {
		// Perform DirectIO along with fdatasync for larger xl.meta, mostly when
		// xl.meta has "inlined data" we prefer writing O_DIRECT and then doing
		// fdatasync() at the end instead of opening the file with O_DSYNC.
		//
		// This is an optimization mainly to ensure faster I/O.
		if len(b) > xioutil.DirectioAlignSize {