diff --git a/weed/util/log_buffer/sealed_buffer.go b/weed/util/log_buffer/sealed_buffer.go
index e412b5f32..cade45dd1 100644
--- a/weed/util/log_buffer/sealed_buffer.go
+++ b/weed/util/log_buffer/sealed_buffer.go
@@ -1,6 +1,9 @@
 package log_buffer
 
-import "time"
+import (
+	"fmt"
+	"time"
+)
 
 type MemBuffer struct {
 	buf       []byte
@@ -53,3 +56,7 @@ func (mb *MemBuffer) locateByTs(lastReadTime time.Time) (pos int) {
 	}
 	return len(mb.buf)
 }
+
+func (mb *MemBuffer) String() string {
+	return fmt.Sprintf("[%v,%v] bytes:%d", mb.startTime, mb.stopTime, mb.size)
+}
\ No newline at end of file