if err != nil {
			t.Fatalf("Test %d: failed to create ErasureStorage: %v", i, err)
		}
		data := make([]byte, test.size)
		if _, err = io.ReadFull(rand.Reader, data); err != nil {
			t.Fatalf("Test %d: failed to create random test data: %v", i, err)
		}
		buffer := make([]byte, test.blocksize, 2*test.blocksize)
		writers := make([]io.Writer, len(disks))