I have a piece of code that works as follows:
[li] Open a TFile in UPDATE mode[/li]
[li] Create a TTree[/li]
[li] Write the TTree to the TFile[/li]
[li] Close the TFile[/li][/ul]
This procedure is repeated a number of times with different (new) TTrees, each having a unique name, but the same TFile (which should work, since it’s opened in UPDATE mode).
It is important to note that I do not know the number or properties of the other TTrees at the time of first call of Write.
However, when running the code, during the write of the second or third TTree (depending on the data), I get the following error message:
file probably overwritten: stopping reporting error messages
===>File is more than 2 Gigabytes
I already tried playing around with TTree::SetMaxTreeSize and TTree::SetMaxVirtualSize, but changing these to a larger value seems to have no effect whatsoever on the error message.
It is of crucial importance that all four TTrees are written to the same TFile, since this is the input format required for later processing, over which I have no control.
FYI, I’m running on lxplus6 with ROOT 5.34/08 and gcc 4.7 sourced from CVMFS. My code is an executable compiled with gcc against the root libraries.
Can anybody help me figure out what’s going on and fix this problem?