Hi, I had one file. When it's in xrootd, TChain.GetEntries() just stuck. But when I copied it locally, TChain.GetEntries() works fine. Do you know what's the problem? The xrootd has no problem. I can easily copy the file with xrdcp from xrootd to local disk. #root command TChain chain("physics"); chain.Add("root:// higgs15.cs.wisc.edu//atlas/xrootd/atlasdownloaddisk/skim/SlimYming/data11_7TeV.00191517.physics_Egamma.merge.NTUP_SMWZ.f413_m1025_p833_tid621784_00/NTUP_SMWZ.621784._000047.root.1 "); Int_t nevent = chain.GetEntries(); -- Best Regards Wen ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-L list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-L&A=1