Re: Large Files

From: M. Sievers (sieversm@mail.desy.de)
Date: Thu Jul 29 1999 - 16:18:21 MEST


Hi,

I know that Linux on 32bit architectures has a 2GB file size limit,
although there are rumours about patches that circumvent this.
Although you seem to use a MAC-PPC, this might apply to your case too.

If the MAC can handle larger files, you might want to experiment with
BASE_File.cxx. It has a line 

 BASE_File.cxx:   Int_t max_file_size = 2000000000;  // should rather
check disk quota

that makes me think this limit is arbitrary. Be careful that there is also
a line
 BASE_File.cxx:      new TFree(fEND,2000000000);

that might have to be changed too.


Bye,
Mike


On Tue, 27 Feb 1940, Norbert Danneberg wrote:

> Hi
> 
> I trying to write a huge Tree to a file. After the filesize reachese
> approx. 2GB the algorith crashes and leaves the file impropper closed.
> 
> -rw-r--r--   1 muptdev  users    1999999972 Jul 28 20:12
> /data_sdc/mt615xNeg_A.cal.root
> -rw-r--r--   1 muptdev  users    1999999995 Jul 29 11:23
> /data_sdc/mt615xPos_A.cal.root
> 
> Is there a limit in file-size ?
> 
> Every time I open the file root recovers 379 keys wich takes some time.
> Ist there a way to permanetly recover the file in such a way that it is
> closed properly afterwards?
> 
> Opening the File in "Updated" mode did also not work. I receive the
> following error:
> 
> root [0] f1 = new TFile("/data_sdc/mt615xPos_A.cal.root","Update");
> Warning in <TFile::TFile>: file /data_sdc/mt615xPos_A.cal.root probably
> not clos
> ed, trying to recover
> Address = 2000000001    Nbytes = 0      =====E R R O R=======
> Error in <TKey::Create>: Cannot allocate 20474 bytes for ID =
> /data_sdc/mt615xPos_A.cal.root Title =

--------------------------------------------------------------------------
Michael Sievers
Michael.Sievers@desy.de
--------------------------------------------------------------------------
Plug-and-Play is really nice, unfortunately it only works 50% of the time.
To be specific the "Plug" almost always works.            --unknown source



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