Hadd and output file limitation

ROOT
1

Dear all,

I’m using hadd to merge several ROOT files in one single output file. In each file there are histograms and trees. There are 500 input files and the expected output file size is about 15GB. But, when the output file size exceeds approx. 10 GB the program switches to a new file _1.root. In a previous topic, Rene suggested to move to version 5.26 where the default tree size is set to 100 GBytes. Well, I’m using version 5.26/00 under LinuxRH9 and I still have this problem. The command I’m using is:

hadd -f output.root input_*.root

I don’t know if this is relevant but the Trees in my files are disk-resident ones.

I’d appreciate any help.
Thanks

2

Hi,

Indeed, hadd was (inadvertently) setting the max to only 10Gb. This is fixed in the trunk by revision 32835.

Cheers,
Philippe.

3

Hi,

Thanks for your answer. How can I fix this? Is there anything I can do to change my current version in order to get it working?

Thanks

4

Hi,

Yes, simply apply the patch

http://root.cern.ch/viewvc/trunk/main/src/hadd.cxx?r1=29998&r2=32835&view=patch

to your version of ROOT and recompile hadd.

Cheers,
Philippe.

5

Hi Philippe,

Thank you again. I have the corrected hadd.cxx. Sorry about the stupid question, but how can I recompile only hadd? I mean, in which directory should I go and what should I type? I’ve tried “make hadd” but it didn’t work.

Thanks.

6

Hi,

Just doing make in the top level of your ROOT source directory should do it (or make bin/hadd).

Cheers,
Philippe.

7

Hi,

Thanks. It worked just fine. I could recompile hadd and now I have my single 15GB ROOT file.
Thank you again.

Cheers,
Sergio