Arugument list too long on Linux System

[Brad Tilley]

I was using Python to tar up some files each day in a directory by 
calling os.popen("/bin/tar.......).
Everything was working well until the app that generated the files was 
set to generate a file every two seconds for nine hours each day (16,200 
files each day). After this I began getting this error:

"Argument list too long"

This would happen from the script or from the command line invoking tar 
natively. So, I wrote my way around this by using this code:

    tar_it = tarfile.open("%s.tar" %real_time, "w")
    for root, dirs, files in os.walk(path):
       for f in files:
          jpg = os.path.splitext(f)
	 ## If the file has a '.jpg' extension add it to the tar file.
          if jpg[1] == '.jpg':
	    tar_it.add(f)

But, I don't understand why I got this error in the first place. I use a 
rather robust Debian GNU\Linux system (3.2GHz proc, 2GB DDR400 RAM, 15K 
SCSI drives) what causes this type of error? This is not really a Python 
issue, but I thought some knowledgeable users on the list might be 
willing to explain it.

Thanks,

Brad