}
									// Update to new config and add current
									valid := 0
									for shardIdx, shard := range splitFilled[:k] {
										shardConfig[shardIdx] = shard[offset]
										valid += int(shard[offset])
										if shard[offset] == 0 {
											shards[shardIdx] = shards[shardIdx][:0]
										} else {

				fmt.Fprintf(os.Stderr, "%v: error on self-test [d:%d,p:%d]: want %#v, got %#v\n", algo, conf[0], conf[1], a, b)
				ok = false
				continue
			}
			// Delete first shard and reconstruct...
			first := encoded[0]
			encoded[0] = nil
			failOnErr(e.DecodeDataBlocks(encoded))
			if a, b := first, encoded[0]; !bytes.Equal(a, b) {

			if test.reconstructParity {
				for j := range decoded {
					if decoded[j] == nil {
						t.Errorf("Test %d: failed to reconstruct shard %d", i, j)
					}
				}
			} else {
				for j := range decoded[:test.dataBlocks] {
					if decoded[j] == nil {
						t.Errorf("Test %d: failed to reconstruct data shard %d", i, j)
					}
				}
			}

			decodedData := new(bytes.Buffer)

	"hash"
	"io"
)

// Implementation to calculate bitrot for the whole file.
type wholeBitrotWriter struct {
	disk      StorageAPI
	volume    string
	filePath  string
	shardSize int64 // This is the shard size of the erasure logic
	hash.Hash       // For bitrot hash
}

func (b *wholeBitrotWriter) Write(p []byte) (int, error) {
	err := b.disk.AppendFile(context.TODO(), b.volume, b.filePath, p)
	if err != nil {

	StandardEnv = "MINIO_STORAGE_CLASS_STANDARD"
	// Optimize storage class environment variable
	OptimizeEnv = "MINIO_STORAGE_CLASS_OPTIMIZE"
	// Inline block indicates the size of the shard
	// that is considered for inlining, remember this
	// shard value is the value per drive shard it
	// will vary based on the parity that is configured
	// for the STANDARD storage_class.
	// inlining means data and metadata are written

				// Reading first time on this disk, hence the buffer needs to be allocated.
				// Subsequent reads will reuse this buffer.
				p.buf[bufIdx] = make([]byte, p.shardSize)
			}
			// For the last shard, the shardsize might be less than previous shard sizes.
			// Hence the following statement ensures that the buffer size is reset to the right size.
			p.buf[bufIdx] = p.buf[bufIdx][:p.shardSize]
			n, err := rr.ReadAt(p.buf[bufIdx], p.offset)

## What is Erasure Code?

- Erasure coding used by MinIO is [Reed-Solomon](https://github.com/klauspost/reedsolomon) erasure coding scheme, which has a total shard maximum of 256 i.e 128 data and 128 parity. MinIO design goes beyond this limitation by doing some practical architecture choices.

			disks := er.getDisks()
			distribution := hashOrder(pathJoin(bucket, object), nDisks)
			shuffledDisks := shuffleDisks(disks, distribution)

			// remove last data shard
			err = removeAll(pathJoin(shuffledDisks[11].String(), bucket, object))
			if err != nil {
				t.Fatalf("Failed to delete a file - %v", err)
			}
			_, err = obj.HealObject(ctx, bucket, object, "", madmin.HealOpts{

	shardSize := int64(1024 * 1024)
	shard := make([]byte, shardSize)
	w := newStreamingBitrotWriter(storage, "", volName, fileName, size, algo, shardSize)
	reader := bytes.NewReader(data)
	for {
		// Using io.Copy instead of this loop will not work for us as io.Copy
		// will use bytes.Reader.WriteTo() which will not do shardSize'ed writes
		// causing error.
		n, err := reader.Read(shard)
		w.Write(shard[:n])