issue 49: unwritable volume become writable after compacting
issue 49: unwritable volume become writable after compacting
k85169336/seaweedfs,k85169336/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs,hxiaodon/seaweedfs,chrislusf/seaweedfs,hxiaodon/seaweedfs,chrislusf/seaweedfs