Dear experts,
I am trying to add 4 root files using hadd command, all files have trees and histograms with the same name.
hadd target.root source1.root source 2.root source 3.root
But I got this message in the terminal.
hadd Target file: all.root
hadd Source file 1: 12_G100000_gen_2_sim_2_digi.root
hadd Source file 2: 14_G100000_gen_2_sim_2_digi.root
hadd Source file 3: M12_G100000_gen_2_sim_2_digi.root
hadd Source file 4: M14_G100000_gen_2_sim_2_digi.root
hadd Target path: all.root:/
SysError in TFile::Flush: error flushing file all.root (Input/output error)
Error in TFile::ReadBuffer: error reading all requested bytes from file all.root, got 0 of 34480
Error in TKey::ReadFile: Failed to read data.
Error R__unzip_header: error in header
Warning in TTree::CopyEntries: The output TTree (T2) must be associated with a writable file (all.root).
Warning in TTree::CopyEntries: The output TTree (T2) must be associated with a writable file (all.root).
Warning in TTree::CopyEntries: The output TTree (T2) must be associated with a writable file (all.root).
Error in TFileMerger::Merge: error during merge of your ROOT files
Please tell me how can I rectify this ?