Problem with a big tree

I have a tree with about 35 branchs and with about 8300 entries for each tree.
If I try to draw some of these branch, I obtain the following error:

Error in : error reading all requested bytes from file 070112_MCAL.out.root, got 0 of 6653

I have changed my software and I have added AutoSave, but the result is the same.
With tree more less events this problema don’t occour.
The program don’t crash at the end of the elaboration.

Thank you very much
Best regards
Andrea Bulgarelli


This could be due to a couple of problems. You file may have grown over 2GB, and the automatically ChangeFile was put in action and you may have not written the correct TFile. You may also have run out of disk space …

So I would need more details to understand the problem (aka send a simple script/tar file reproducing the problem )