diff --git a/weed/filesys/dirty_pages_mem_chunk.go b/weed/filesys/dirty_pages_mem_chunk.go
index 7e8dc0b05..fc5669ec0 100644
--- a/weed/filesys/dirty_pages_mem_chunk.go
+++ b/weed/filesys/dirty_pages_mem_chunk.go
@@ -27,7 +27,7 @@ func newMemoryChunkPages(fh *FileHandle, chunkSize int64) *MemoryChunkPages {
 		fh: fh,
 	}
 
-	dirtyPages.uploadPipeline = page_writer.NewUploadPipeline(
+	dirtyPages.uploadPipeline = page_writer.NewUploadPipeline(fh.f.fullpath(),
 		fh.f.wfs.concurrentWriters, chunkSize, dirtyPages.saveChunkedFileIntevalToStorage)
 
 	return dirtyPages
diff --git a/weed/filesys/page_writer/upload_pipeline.go b/weed/filesys/page_writer/upload_pipeline.go
index 2fb1bbf52..83e5c8b60 100644
--- a/weed/filesys/page_writer/upload_pipeline.go
+++ b/weed/filesys/page_writer/upload_pipeline.go
@@ -1,6 +1,7 @@
 package page_writer
 
 import (
+	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/util"
 	"github.com/chrislusf/seaweedfs/weed/util/mem"
@@ -18,6 +19,7 @@ type UploadPipeline struct {
 	activeWriterCond   *sync.Cond
 	activeWriterCount  int32
 	saveToStorageFn    SaveToStorageFunc
+	filepath           util.FullPath
 }
 
 type SealedChunk struct {
@@ -25,14 +27,15 @@ type SealedChunk struct {
 	referenceCounter int // track uploading or reading processes
 }
 
-func (sc *SealedChunk) FreeReference() {
+func (sc *SealedChunk) FreeReference(messageOnFree string) {
 	sc.referenceCounter--
 	if sc.referenceCounter == 0 {
+		glog.V(4).Infof("Free sealed chunk: %s", messageOnFree)
 		mem.Free(sc.chunk.buf)
 	}
 }
 
-func NewUploadPipeline(writers *util.LimitedConcurrentExecutor, chunkSize int64, saveToStorageFn SaveToStorageFunc) *UploadPipeline {
+func NewUploadPipeline(filepath util.FullPath, writers *util.LimitedConcurrentExecutor, chunkSize int64, saveToStorageFn SaveToStorageFunc) *UploadPipeline {
 	return &UploadPipeline{
 		ChunkSize:        chunkSize,
 		writableChunks:   make(map[LogicChunkIndex]*MemChunk),
@@ -40,6 +43,7 @@ func NewUploadPipeline(writers *util.LimitedConcurrentExecutor, chunkSize int64,
 		writers:          writers,
 		activeWriterCond: sync.NewCond(&sync.Mutex{}),
 		saveToStorageFn:  saveToStorageFn,
+		filepath:         filepath,
 	}
 }
 
@@ -77,7 +81,7 @@ func (cw *UploadPipeline) MaybeReadDataAt(p []byte, off int64) (maxStop int64) {
 	cw.sealedChunksLock.Unlock()
 	if found {
 		maxStop = readMemChunk(sealedChunk.chunk, p, off, logicChunkIndex, cw.ChunkSize)
-		sealedChunk.FreeReference()
+		sealedChunk.FreeReference(fmt.Sprintf("%s finish reading chunk %d", cw.filepath, logicChunkIndex))
 	}
 
 	// read from writable chunks last
@@ -125,12 +129,12 @@ func (cw *UploadPipeline) maybeMoveToSealed(memChunk *MemChunk, logicChunkIndex
 
 func (cw *UploadPipeline) moveToSealed(memChunk *MemChunk, logicChunkIndex LogicChunkIndex) {
 	atomic.AddInt32(&cw.activeWriterCount, 1)
-	glog.V(4).Infof("activeWriterCount %d ++> %d", cw.activeWriterCount-1, cw.activeWriterCount)
+	glog.V(4).Infof("%s activeWriterCount %d ++> %d", cw.filepath, cw.activeWriterCount-1, cw.activeWriterCount)
 
 	cw.sealedChunksLock.Lock()
 
 	if oldMemChunk, found := cw.sealedChunks[logicChunkIndex]; found {
-		oldMemChunk.FreeReference()
+		oldMemChunk.FreeReference(fmt.Sprintf("%s replace chunk %d", cw.filepath, logicChunkIndex))
 	}
 	sealedChunk := &SealedChunk{
 		chunk:            memChunk,
@@ -149,10 +153,10 @@ func (cw *UploadPipeline) moveToSealed(memChunk *MemChunk, logicChunkIndex Logic
 		cw.sealedChunksLock.Lock()
 		defer cw.sealedChunksLock.Unlock()
 		delete(cw.sealedChunks, logicChunkIndex)
-		sealedChunk.FreeReference()
+		sealedChunk.FreeReference(fmt.Sprintf("%s finished uploading chunk %d", cw.filepath, logicChunkIndex))
 
 		atomic.AddInt32(&cw.activeWriterCount, -1)
-		glog.V(4).Infof("activeWriterCount %d --> %d", cw.activeWriterCount+1, cw.activeWriterCount)
+		glog.V(4).Infof("%s activeWriterCount %d --> %d", cw.filepath, cw.activeWriterCount+1, cw.activeWriterCount)
 		// Lock and Unlock are not required,
 		// but it may signal multiple times during one wakeup,
 		// and the waiting goroutine may miss some of them!