diff --git a/weed/filer2/reader_at.go b/weed/filer2/reader_at.go
index 697e3f630..0ab456d79 100644
--- a/weed/filer2/reader_at.go
+++ b/weed/filer2/reader_at.go
@@ -114,7 +114,7 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
 
 func (c *ChunkReadAt) fetchChunkData(chunkView *ChunkView) (data []byte, err error) {
 
-	// fmt.Printf("fetching %s [%d,%d)\n", chunkView.FileId, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size))
+	glog.V(4).Infof("fetchChunkData %s [%d,%d)\n", chunkView.FileId, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size))
 
 	hasDataInCache := false
 	chunkData := c.chunkCache.GetChunk(chunkView.FileId, chunkView.ChunkSize)
diff --git a/weed/util/chunk_cache/chunk_cache.go b/weed/util/chunk_cache/chunk_cache.go
index 9421ac15c..ca26e1f77 100644
--- a/weed/util/chunk_cache/chunk_cache.go
+++ b/weed/util/chunk_cache/chunk_cache.go
@@ -76,6 +76,8 @@ func (c *ChunkCache) SetChunk(fileId string, data []byte) {
 	c.Lock()
 	defer c.Unlock()
 
+	glog.V(4).Infof("SetChunk %s size %d\n", fileId, len(data))
+
 	c.doSetChunk(fileId, data)
 }
 
diff --git a/weed/util/chunk_cache/chunk_cache_on_disk.go b/weed/util/chunk_cache/chunk_cache_on_disk.go
index 2c7ef8d39..d74f87b0c 100644
--- a/weed/util/chunk_cache/chunk_cache_on_disk.go
+++ b/weed/util/chunk_cache/chunk_cache_on_disk.go
@@ -138,7 +138,7 @@ func (v *ChunkCacheVolume) WriteNeedle(key types.NeedleId, data []byte) error {
 	}
 
 	if err := v.nm.Put(key, types.ToOffset(offset), uint32(len(data))); err != nil {
-		glog.V(4).Infof("failed to save in needle map %d: %v", key, err)
+		return err
 	}
 
 	return nil
diff --git a/weed/util/chunk_cache/on_disk_cache_layer.go b/weed/util/chunk_cache/on_disk_cache_layer.go
index 9cf8e3ab2..c3192b548 100644
--- a/weed/util/chunk_cache/on_disk_cache_layer.go
+++ b/weed/util/chunk_cache/on_disk_cache_layer.go
@@ -54,7 +54,9 @@ func (c *OnDiskCacheLayer) setChunk(needleId types.NeedleId, data []byte) {
 		c.diskCaches[0] = t
 	}
 
-	c.diskCaches[0].WriteNeedle(needleId, data)
+	if err := c.diskCaches[0].WriteNeedle(needleId, data); err != nil {
+		glog.V(0).Infof("cache write %v size %d: %v", needleId, len(data), err)
+	}
 
 }