How　to　improve　the　performance　of　single　failure　recovery　has　been　an　active　research　topic　because　of　its　prevalence　in　large-scale　storage　systems.　We　argue　that　when　erasure　coding　is　deployed　in　a　clustered　file　system　(CFS),　existing　single　failure　recovery　designs　are　limited　in　different　aspects:　neglecting　the　bandwidth　diversity　property　in　a　CFS　architecture,　targeting　specific　erasure　code　constructions,　and　no　special　treatment　on　load　balancing　during　recovery.　In　this　paper,　we　propose　CAR,　a　cross-rack-aware　recovery　algorithm　that　is　designed　to　improve　the　performance　of　single　failure　recovery　of　a　CFS　that　employs　Reed-Solomon　codes　for　general　fault　tolerance.　For　each　stripe,　CAR　finds　a　recovery　solution　that　retrieves　data　from　the　minimum　number　of　racks.　It　also　reduces　the　amount　of　cross-rack　repair　traffic　by　performing　intra-rack　data　aggregation　prior　to　cross-rack　transmission.　Furthermore,　by　considering　multi-stripe　recovery,　CAR　balances　the　amount　of　cross-rack　repair　traffic　across　multiple　racks.　Evaluation　results　show　that　CAR　can　effectively　reduce　the　amount　of　cross-rack　repair　traffic　and　the　resulting　recovery　time.　©　2004-2012　IEEE.