- MinIO does erasure coding at the object level not at the volume level, unlike other object storage vendors. This allows applications to choose different storage class by setting `x-amz-storage-class=STANDARD/REDUCED_REDUNDANCY` for each object uploads so effectively utilizing the capacity of the cluster. Additionally these can also be enforced using IAM policies to make sure the client uploads with correct HTTP headers.

./mc mb sitea/testbucket

./mc version enable sitea/testbucket

./mc put --quiet README.md sitea/testbucket/file
etag1=$(./mc cat sitea/testbucket/file | md5sum --tag | awk {'print $4'})

./mc cp --quiet --storage-class "STANDARD" sitea/testbucket/file sitea/testbucket/file
etag2=$(./mc cat sitea/testbucket/file | md5sum --tag | awk {'print $4'})
if [ $etag1 != $etag2 ]; then
	echo "expected $etag1, got $etag2"
	exit 1
fi

	if err != nil {
		return err
	}
	*n = NoncurrentVersionTransition(val)
	n.set = true
	return nil
}

// IsNull returns true if NoncurrentTransition doesn't refer to any storage-class.
// Note: It supports immediate transition, i.e zero noncurrent days.
func (n NoncurrentVersionTransition) IsNull() bool {
	return n.StorageClass == ""
}

// Validate returns an error with wrong value

func (gcs *warmBackendGCS) Put(ctx context.Context, key string, data io.Reader, length int64) (remoteVersionID, error) {
	object := gcs.client.Bucket(gcs.Bucket).Object(gcs.getDest(key))
	// TODO: set storage class
	w := object.NewWriter(ctx)
	if gcs.StorageClass != "" {
		w.ObjectAttrs.StorageClass = gcs.StorageClass
	}
	if _, err := xioutil.Copy(w, data); err != nil {
		return "", gcsToObjectError(err, gcs.Bucket, key)
	}

### Consistency Guarantees