Change the default maximum TTree size

Hello Rene and thanks for your reply!

I'm sorry, I realize I was a bit unclear in my last post. I meant "you" as in anyone in general, not the developers of root. I should have written "can I change the line in the TTree.h file" and recompile on my own computer to get the desired new default. Sorry for the misunderstanding... The statement you suggested, does that change the max size forever, or only for the root instance you are running at the moment? /Ida

Den 3 november 2009 10.18 skrev Rene Brun <Rene.Brun_at_cern.ch>:

No, we will not change the MaxTreeSize for several reasons.
> It is trivial to change it yourself with a statement like
> //Authorize Trees up to 2 Terabytes (if the system can do it)
> TTree::SetMaxTreeSize(1000*Long64_t(2000000000));
>
> Rene Brun
>
>
> Ida Häggström wrote:
>
>> Hello!
>>
>> I'm a new ROOT-user (version 5.24) and have a question regarding the
>> maximum TTree file size. I'm running a Monte Carlo simulation software
>> called Gate (based on Geant4) which produces ROOT output. I've understood
>> the maximum allowed file size by default is 1.9GB, but could be changed to
>> something larger if your OS allows it. I run CentOS 5 Linux with file system
>> ext3 and I think the maximum size should be at least 16GB. I've briefed
>> through the forum and users guide and found that you can change the maximum
>> allowed size via the command TTree::SetMaxTreeSize(). This only applies for
>> that particular instance of ROOT however (right?), when you exit and start a
>> new ROOT you have your default settings again. Using Gate, I never open ROOT
>> myself during the creation of the output files... I wonder if you can change
>> the default 1.9GB to say 16GB instead? In the TTree.h file, line 393
>>
>> static void SetMaxTreeSize(Long64_t maxsize = 1900000000);
>>
>> Can you change the size here and recompile Root to get the new default??
>> Thank you!
>> Ida
>>
>
>
Received on Tue Nov 03 2009 - 10:56:45 CET