diff --git a/go/operation/chunked_file.go b/go/operation/chunked_file.go
index 70564cbd2..786b8a989 100644
--- a/go/operation/chunked_file.go
+++ b/go/operation/chunked_file.go
@@ -74,7 +74,7 @@ func (cm *ChunkManifest) DeleteChunks(master string) error {
 	for _, ci := range cm.Chunks {
 		if e := DeleteFile(master, ci.Fid, ""); e != nil {
 			deleteError++
-			glog.V(0).Infof("Delete %s error: %s, master: %s", ci.Fid, e.Error(), master)
+			glog.V(0).Infof("Delete %s error: %v, master: %s", ci.Fid, e, master)
 		}
 	}
 	if deleteError > 0 {
diff --git a/go/operation/delete_content.go b/go/operation/delete_content.go
index 32ad69b17..c808cc75a 100644
--- a/go/operation/delete_content.go
+++ b/go/operation/delete_content.go
@@ -3,6 +3,7 @@ package operation
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/url"
 	"strings"
 	"sync"
@@ -23,9 +24,13 @@ type DeleteResult struct {
 func DeleteFile(master string, fileId string, jwt security.EncodedJwt) error {
 	fileUrl, err := LookupFileId(master, fileId)
 	if err != nil {
-		return err
+		return fmt.Errorf("Failed to lookup %s:%v", fileId, err)
 	}
-	return util.Delete(fileUrl, jwt)
+	err = util.Delete(fileUrl, jwt)
+	if err != nil {
+		return fmt.Errorf("Failed to delete %s:%v", fileUrl, err)
+	}
+	return nil
 }
 
 func ParseFileId(fid string) (vid string, key_cookie string, err error) {
diff --git a/go/operation/submit.go b/go/operation/submit.go
index d996d63f0..18484680a 100644
--- a/go/operation/submit.go
+++ b/go/operation/submit.go
@@ -4,13 +4,12 @@ import (
 	"bytes"
 	"io"
 	"mime"
+	"net/url"
 	"os"
 	"path"
 	"strconv"
 	"strings"
 
-	"net/url"
-
 	"github.com/chrislusf/seaweedfs/go/glog"
 	"github.com/chrislusf/seaweedfs/go/security"
 )
@@ -188,7 +187,7 @@ func upload_chunked_file_manifest(fileUrl string, manifest *ChunkManifest, jwt s
 	glog.V(4).Info("Uploading chunks manifest ", manifest.Name, " to ", fileUrl, "...")
 	u, _ := url.Parse(fileUrl)
 	q := u.Query()
-	q.Set("cm", "1")
+	q.Set("cm", "true")
 	u.RawQuery = q.Encode()
 	_, e = Upload(u.String(), manifest.Name, bufReader, false, "application/json", jwt)
 	return e
diff --git a/go/storage/needle.go b/go/storage/needle.go
index 32ebdae7d..e49368820 100644
--- a/go/storage/needle.go
+++ b/go/storage/needle.go
@@ -14,8 +14,8 @@ import (
 
 	"github.com/chrislusf/seaweedfs/go/glog"
 	"github.com/chrislusf/seaweedfs/go/images"
-	"github.com/chrislusf/seaweedfs/go/util"
 	"github.com/chrislusf/seaweedfs/go/operation"
+	"github.com/chrislusf/seaweedfs/go/util"
 )
 
 const (
@@ -53,7 +53,9 @@ func (n *Needle) String() (str string) {
 	return
 }
 
-func ParseUpload(r *http.Request) (fileName string, data []byte, mimeType string, isGzipped bool, modifiedTime uint64, ttl *TTL, isChunkedFile bool, e error) {
+func ParseUpload(r *http.Request) (
+	fileName string, data []byte, mimeType string, isGzipped bool,
+	modifiedTime uint64, ttl *TTL, isChunkedFile bool, e error) {
 	form, fe := r.MultipartReader()
 	if fe != nil {
 		glog.V(0).Infoln("MultipartReader [ERROR]", fe)
@@ -163,7 +165,7 @@ func NewNeedle(r *http.Request, fixJpgOrientation bool) (n *Needle, e error) {
 	}
 
 	if isChunkedFile {
-		n.SetChunkManifest()
+		n.SetIsChunkManifest()
 	}
 
 	if fixJpgOrientation {
diff --git a/go/storage/needle_read_write.go b/go/storage/needle_read_write.go
index 9d7af600a..ccfe1d498 100644
--- a/go/storage/needle_read_write.go
+++ b/go/storage/needle_read_write.go
@@ -16,7 +16,7 @@ const (
 	FlagHasMime             = 0x04
 	FlagHasLastModifiedDate = 0x08
 	FlagHasTtl              = 0x10
-	FlagChunkManifest       = 0x80
+	FlagIsChunkManifest     = 0x80
 	LastModifiedBytesLength = 5
 	TtlBytesLength          = 2
 )
@@ -283,9 +283,9 @@ func (n *Needle) SetHasTtl() {
 }
 
 func (n *Needle) IsChunkedManifest() bool {
-	return n.Flags&FlagChunkManifest > 0
+	return n.Flags&FlagIsChunkManifest > 0
 }
 
-func (n *Needle) SetChunkManifest() {
-	n.Flags = n.Flags | FlagChunkManifest
+func (n *Needle) SetIsChunkManifest() {
+	n.Flags = n.Flags | FlagIsChunkManifest
 }
diff --git a/go/util/http_util.go b/go/util/http_util.go
index f80ab0c24..29b2043ee 100644
--- a/go/util/http_util.go
+++ b/go/util/http_util.go
@@ -2,6 +2,8 @@ package util
 
 import (
 	"bytes"
+	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -9,10 +11,7 @@ import (
 	"net/url"
 	"strings"
 
-	"encoding/json"
-
 	"github.com/chrislusf/seaweedfs/go/security"
-	"github.com/syndtr/goleveldb/leveldb/errors"
 )
 
 var (
diff --git a/go/weed/download.go b/go/weed/download.go
index dfe4f88b4..2e948a056 100644
--- a/go/weed/download.go
+++ b/go/weed/download.go
@@ -3,11 +3,9 @@ package main
 import (
 	"fmt"
 	"io"
+	"io/ioutil"
 	"os"
 	"path"
-
-	"io/ioutil"
-
 	"strings"
 
 	"github.com/chrislusf/seaweedfs/go/operation"
diff --git a/go/weed/weed_server/volume_server_handlers_read.go b/go/weed/weed_server/volume_server_handlers_read.go
index 2aa0fc656..bfa6d6a4f 100644
--- a/go/weed/weed_server/volume_server_handlers_read.go
+++ b/go/weed/weed_server/volume_server_handlers_read.go
@@ -1,18 +1,16 @@
 package weed_server
 
 import (
+	"bytes"
 	"io"
 	"mime"
 	"mime/multipart"
 	"net/http"
+	"path"
 	"strconv"
 	"strings"
 	"time"
 
-	"path"
-
-	"bytes"
-
 	"github.com/chrislusf/seaweedfs/go/glog"
 	"github.com/chrislusf/seaweedfs/go/images"
 	"github.com/chrislusf/seaweedfs/go/operation"
@@ -135,15 +133,10 @@ func (vs *VolumeServer) tryHandleChunkedFile(n *storage.Needle, fileName string,
 	if !n.IsChunkedManifest() {
 		return false
 	}
-	raw, _ := strconv.ParseBool(r.FormValue("raw"))
-	if raw {
-		return false
-	}
-	processed = true
 
 	chunkManifest, e := operation.LoadChunkManifest(n.Data, n.IsGzipped())
 	if e != nil {
-		glog.V(0).Infof("load chunked manifest (%s) error: %s", r.URL.Path, e.Error())
+		glog.V(0).Infof("load chunked manifest (%s) error: %v", r.URL.Path, e)
 		return false
 	}
 	if fileName == "" && chunkManifest.Name != "" {
@@ -167,7 +160,7 @@ func (vs *VolumeServer) tryHandleChunkedFile(n *storage.Needle, fileName string,
 	if e := writeResponseContent(fileName, mType, chunkedFileReader, w, r); e != nil {
 		glog.V(2).Infoln("response write error:", e)
 	}
-	return
+	return true
 }
 
 func writeResponseContent(filename, mimeType string, rs io.ReadSeeker, w http.ResponseWriter, r *http.Request) error {
diff --git a/go/weed/weed_server/volume_server_handlers_write.go b/go/weed/weed_server/volume_server_handlers_write.go
index 1f0fa96dd..3d2afaf77 100644
--- a/go/weed/weed_server/volume_server_handlers_write.go
+++ b/go/weed/weed_server/volume_server_handlers_write.go
@@ -2,6 +2,7 @@ package weed_server
 
 import (
 	"errors"
+	"fmt"
 	"net/http"
 
 	"github.com/chrislusf/seaweedfs/go/glog"
@@ -72,12 +73,12 @@ func (vs *VolumeServer) DeleteHandler(w http.ResponseWriter, r *http.Request) {
 	if n.IsChunkedManifest() {
 		chunkManifest, e := operation.LoadChunkManifest(n.Data, n.IsGzipped())
 		if e != nil {
-			writeJsonError(w, r, http.StatusInternalServerError, errors.New("Load chunks manifest error: "+e.Error()))
+			writeJsonError(w, r, http.StatusInternalServerError, fmt.Errorf("Load chunks manifest error: %v", e))
 			return
 		}
 		// make sure all chunks had deleted before delete manifest
 		if e := chunkManifest.DeleteChunks(vs.GetMasterNode()); e != nil {
-			writeJsonError(w, r, http.StatusInternalServerError, errors.New("Delete chunks error: "+e.Error()))
+			writeJsonError(w, r, http.StatusInternalServerError, fmt.Errorf("Delete chunks error: %v", e))
 			return
 		}
 		count = chunkManifest.Size
@@ -123,11 +124,10 @@ func (vs *VolumeServer) batchDeleteHandler(w http.ResponseWriter, r *http.Reques
 		}
 
 		if n.IsChunkedManifest() {
-			//Don't allow delete manifest in batch delete mode
 			ret = append(ret, operation.DeleteResult{
 				Fid:    fid,
 				Status: http.StatusNotAcceptable,
-				Error:  "ChunkManifest: not allow.",
+				Error:  "ChunkManifest: not allowed in batch delete mode.",
 			})
 			continue
 		}