diff --git a/cmd/bitrot-streaming.go b/cmd/bitrot-streaming.go
index 7104c00ad..e653d2848 100644
--- a/cmd/bitrot-streaming.go
+++ b/cmd/bitrot-streaming.go
@@ -32,19 +32,9 @@ type streamingBitrotWriter struct {
 	h         hash.Hash
 	shardSize int64
 	canClose  chan struct{} // Needed to avoid race explained in Close() call.
-
-	// Following two fields are used only to make sure that Write(p) is called such that
-	// len(p) is always the block size except the last block, i.e prevent programmer errors.
-	currentBlockIdx int
-	verifyTillIdx   int
 }
 
 func (b *streamingBitrotWriter) Write(p []byte) (int, error) {
-	if b.currentBlockIdx < b.verifyTillIdx && int64(len(p)) != b.shardSize {
-		// All blocks except last should be of the length b.shardSize
-		logger.LogIf(context.Background(), errUnexpected)
-		return 0, errUnexpected
-	}
 	if len(p) == 0 {
 		return 0, nil
 	}
@@ -57,7 +47,6 @@ func (b *streamingBitrotWriter) Write(p []byte) (int, error) {
 		return 0, err
 	}
 	n, err = b.iow.Write(p)
-	b.currentBlockIdx++
 	return n, err
 }
 
@@ -78,10 +67,13 @@ func (b *streamingBitrotWriter) Close() error {
 func newStreamingBitrotWriter(disk StorageAPI, volume, filePath string, length int64, algo BitrotAlgorithm, shardSize int64) io.WriteCloser {
 	r, w := io.Pipe()
 	h := algo.New()
-	bw := &streamingBitrotWriter{w, h, shardSize, make(chan struct{}), 0, int(length / shardSize)}
+	bw := &streamingBitrotWriter{w, h, shardSize, make(chan struct{})}
 	go func() {
-		bitrotSumsTotalSize := ceilFrac(length, shardSize) * int64(h.Size()) // Size used for storing bitrot checksums.
-		totalFileSize := bitrotSumsTotalSize + length
+		totalFileSize := int64(-1) // For compressed objects length will be unknown (represented by length=-1)
+		if length != -1 {
+			bitrotSumsTotalSize := ceilFrac(length, shardSize) * int64(h.Size()) // Size used for storing bitrot checksums.
+			totalFileSize = bitrotSumsTotalSize + length
+		}
 		err := disk.CreateFile(volume, filePath, totalFileSize, r)
 		if err != nil {
 			reqInfo := (&logger.ReqInfo{}).AppendTags("storageDisk", disk.String())
diff --git a/cmd/bitrot-whole.go b/cmd/bitrot-whole.go
index 2bb43ec51..2416e687c 100644
--- a/cmd/bitrot-whole.go
+++ b/cmd/bitrot-whole.go
@@ -31,19 +31,9 @@ type wholeBitrotWriter struct {
 	filePath  string
 	shardSize int64 // This is the shard size of the erasure logic
 	hash.Hash       // For bitrot hash
-
-	// Following two fields are used only to make sure that Write(p) is called such that
-	// len(p) is always the block size except the last block and prevent programmer errors.
-	currentBlockIdx int
-	lastBlockIdx    int
 }
 
 func (b *wholeBitrotWriter) Write(p []byte) (int, error) {
-	if b.currentBlockIdx < b.lastBlockIdx && int64(len(p)) != b.shardSize {
-		// All blocks except last should be of the length b.shardSize
-		logger.LogIf(context.Background(), errUnexpected)
-		return 0, errUnexpected
-	}
 	err := b.disk.AppendFile(b.volume, b.filePath, p)
 	if err != nil {
 		logger.LogIf(context.Background(), err)
@@ -54,7 +44,6 @@ func (b *wholeBitrotWriter) Write(p []byte) (int, error) {
 		logger.LogIf(context.Background(), err)
 		return 0, err
 	}
-	b.currentBlockIdx++
 	return len(p), nil
 }
 
@@ -63,8 +52,8 @@ func (b *wholeBitrotWriter) Close() error {
 }
 
 // Returns whole-file bitrot writer.
-func newWholeBitrotWriter(disk StorageAPI, volume, filePath string, length int64, algo BitrotAlgorithm, shardSize int64) io.WriteCloser {
-	return &wholeBitrotWriter{disk, volume, filePath, shardSize, algo.New(), 0, int(length / shardSize)}
+func newWholeBitrotWriter(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm, shardSize int64) io.WriteCloser {
+	return &wholeBitrotWriter{disk, volume, filePath, shardSize, algo.New()}
 }
 
 // Implementation to verify bitrot for the whole file.
diff --git a/cmd/bitrot.go b/cmd/bitrot.go
index 383e5dfbc..14a7bde4a 100644
--- a/cmd/bitrot.go
+++ b/cmd/bitrot.go
@@ -120,7 +120,7 @@ func newBitrotWriter(disk StorageAPI, volume, filePath string, length int64, alg
 	if algo == HighwayHash256S {
 		return newStreamingBitrotWriter(disk, volume, filePath, length, algo, shardSize)
 	}
-	return newWholeBitrotWriter(disk, volume, filePath, length, algo, shardSize)
+	return newWholeBitrotWriter(disk, volume, filePath, algo, shardSize)
 }
 
 func newBitrotReader(disk StorageAPI, bucket string, filePath string, tillOffset int64, algo BitrotAlgorithm, sum []byte, shardSize int64) io.ReaderAt {
diff --git a/cmd/erasure.go b/cmd/erasure.go
index 7dfa1242b..5d60af06d 100644
--- a/cmd/erasure.go
+++ b/cmd/erasure.go
@@ -103,6 +103,9 @@ func (e *Erasure) ShardFileSize(totalLength int64) int64 {
 	if totalLength == 0 {
 		return 0
 	}
+	if totalLength == -1 {
+		return -1
+	}
 	numShards := totalLength / e.blockSize
 	lastBlockSize := totalLength % int64(e.blockSize)
 	lastShardSize := ceilFrac(lastBlockSize, int64(e.dataBlocks))
diff --git a/cmd/posix.go b/cmd/posix.go
index 2f1ef0b9f..7936d553a 100644
--- a/cmd/posix.go
+++ b/cmd/posix.go
@@ -187,7 +187,7 @@ func newPosix(path string) (*posix, error) {
 	p := &posix{
 		connected: true,
 		diskPath:  path,
-		// 1MiB buffer pool for posix internal operations.
+		// 4MiB buffer pool for posix internal operations.
 		pool: sync.Pool{
 			New: func() interface{} {
 				b := directio.AlignedBlock(posixWriteBlockSize)
@@ -1028,10 +1028,9 @@ func (s *posix) ReadFileStream(volume, path string, offset, length int64) (io.Re
 
 // CreateFile - creates the file.
 func (s *posix) CreateFile(volume, path string, fileSize int64, r io.Reader) (err error) {
-	if fileSize < 0 {
+	if fileSize < -1 {
 		return errInvalidArgument
 	}
-
 	defer func() {
 		if err == errFaultyDisk {
 			atomic.AddInt32(&s.ioErrCount, 1)
@@ -1120,69 +1119,69 @@ func (s *posix) CreateFile(volume, path string, fileSize int64, r io.Reader) (er
 	defer s.pool.Put(bufp)
 
 	buf := *bufp
-	var written int64
-	dioCount := int(fileSize) / len(buf)
-	for i := 0; i < dioCount; i++ {
+
+	// Writes remaining bytes in the buffer.
+	writeRemaining := func(w *os.File, buf []byte) (remainingWritten int, err error) {
 		var n int
-		_, err = io.ReadFull(r, buf)
-		if err != nil {
-			return err
-		}
-		n, err = w.Write(buf)
-		if err != nil {
-			return err
-		}
-		written += int64(n)
-	}
-	// The following logic writes the remainging data such that it writes whatever best is possible (aligned buffer)
-	// in O_DIRECT mode and remaining (unaligned buffer) in non-O_DIRECT mode.
-	remaining := fileSize % int64(len(buf))
-	if remaining != 0 {
-		buf = buf[:remaining]
-		_, err = io.ReadFull(r, buf)
-		if err != nil {
-			return err
-		}
+		remaining := len(buf)
+		// The following logic writes the remainging data such that it writes whatever best is possible (aligned buffer)
+		// in O_DIRECT mode and remaining (unaligned buffer) in non-O_DIRECT mode.
 		remainingAligned := (remaining / directioAlignSize) * directioAlignSize
 		remainingAlignedBuf := buf[:remainingAligned]
 		remainingUnalignedBuf := buf[remainingAligned:]
 		if len(remainingAlignedBuf) > 0 {
-			var n int
 			n, err = w.Write(remainingAlignedBuf)
 			if err != nil {
-				return err
+				return 0, err
 			}
-			written += int64(n)
+			remainingWritten += n
 		}
 		if len(remainingUnalignedBuf) > 0 {
-			var n int
 			// Write on O_DIRECT fds fail if buffer is not 4K aligned, hence disable O_DIRECT.
 			if err = disk.DisableDirectIO(w); err != nil {
-				return err
+				return 0, err
 			}
 			n, err = w.Write(remainingUnalignedBuf)
 			if err != nil {
-				return err
+				return 0, err
 			}
-			written += int64(n)
+			remainingWritten += n
 		}
+		return remainingWritten, nil
 	}
 
-	// Do some sanity checks.
-	_, err = io.ReadFull(r, buf)
-	if err != io.EOF {
-		return errMoreData
-	}
-
-	if written < fileSize {
-		return errLessData
-	}
-
-	if written > fileSize {
-		return errMoreData
+	var written int
+	for {
+		var n int
+		n, err = io.ReadFull(r, buf)
+		switch err {
+		case nil:
+			n, err = w.Write(buf)
+			if err != nil {
+				return err
+			}
+			written += n
+		case io.ErrUnexpectedEOF:
+			n, err = writeRemaining(w, buf[:n])
+			if err != nil {
+				return err
+			}
+			written += n
+			fallthrough
+		case io.EOF:
+			if fileSize != -1 {
+				if written < int(fileSize) {
+					return errLessData
+				}
+				if written > int(fileSize) {
+					return errMoreData
+				}
+			}
+			return nil
+		default:
+			return err
+		}
 	}
-
-	return nil
 }
 
 func (s *posix) WriteAll(volume, path string, buf []byte) (err error) {
diff --git a/cmd/xl-v1-utils.go b/cmd/xl-v1-utils.go
index 74a2da693..11b3d81fd 100644
--- a/cmd/xl-v1-utils.go
+++ b/cmd/xl-v1-utils.go
@@ -350,6 +350,9 @@ func calculatePartSizeFromIdx(ctx context.Context, totalSize int64, partSize int
 		logger.LogIf(ctx, errPartSizeIndex)
 		return 0, errPartSizeIndex
 	}
+	if totalSize == -1 {
+		return -1, nil
+	}
 	if totalSize > 0 {
 		// Compute the total count of parts
 		partsCount := totalSize/partSize + 1