From 3a8746ca545b991e548c1253de4c34b6d0a2c39b Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Thu, 10 Aug 2017 10:26:19 -0700
Subject: [PATCH] better error message

---
 weed/topology/node.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/weed/topology/node.go b/weed/topology/node.go
index 206a9aff4..5dac4966b 100644
--- a/weed/topology/node.go
+++ b/weed/topology/node.go
@@ -168,7 +168,7 @@ func (n *NodeImpl) ReserveOneVolume(r int) (assignedNode *DataNode, err error) {
 			}
 		}
 	}
-	return
+	return nil, errors.New("No free volume slot found!")
 }
 
 func (n *NodeImpl) UpAdjustMaxVolumeCountDelta(maxVolumeCountDelta int) { //can be negative