I’m trying to merge several root files to one big file where some cuts have already been applied. Therefore I’m creating a TChain containing the root files. Then I’m copying this chain with
TTree *cuttedcopy = chain->CopyTree(myCuts);
Afterwards I’m opening a file and want to write the created tree to this file with
TFile *out = new TFile(filename, "RECREATE"); cuttedcopy->Write(); out->Close();
Now I get different behaviours. If I just add a single file to the chain everything works perfect. But if I try to add more files to the chain I reach a point where things are getting strange. If I specify the file name as relative path, e.g. “cutted.root” I get the error
SysError in TFile::TFile: file cutted.root can not be opened (Permission denied)
This worked with the single file so I should have write privileges. Now if I specify the file name as absolute path, e.g. “/home/mathias/cutted.root” I just get the error that the operation was aborted.
Any ideas on that? Is there perhaps a limitation on the size of root-files? The final size of the file to be written on disk should be something like 250 MB which is not so much. I thought root could handle this. At least there should be no problems with my SuSE 9.3 and ReiserFS to handle these filesizes.
Thx for any hint,