message: adding alaias for PB (aliendu)
diff: @@ -465,6 +465,7 @@ TTree * AliSysInfo::MakeDUTree(const char *lname, const char * fout){
  tree->SetAlias("sizeMB","size/(1024)");
  tree->SetAlias("sizeGB","size/(1024*1024)");
  tree->SetAlias("sizeTB","size/(1024*1024*1024)");
  + tree->SetAlias("sizePB","size/(1024*1024*1024*1024)");
  tree->Write();
  ftout->Close();
  ftout=TFile::Open(fout);
  