Dealing with large memory under linux or How to Build 64bit Python

[prote...@gmail.com]

I've got an Ubuntu (2.6.27-9-server SMP i686 GNU/Linux) setup with
6GB RAM running python 2.5. I'm running a simulation program that is
breaking as soon as it hits ~3GB RAM even though I have plenty of RAM
free. I'm guessing that it's because my python is only 32-bit?

Appreciate any pointers on how to get my app to be capable of using
the full amount of RAM. I'm anticipating this may require me to
rebuild python from scratch for 64bits but I can't find instructions
on how to do that. Appreciate any help in this matter.

-- Ben Scherrey

["Martin v. Löwis"]

> I've got an Ubuntu (2.6.27-9-server SMP i686 GNU/Linux) setup with
> 6GB RAM running python 2.5. I'm running a simulation program that is
> breaking as soon as it hits ~3GB RAM even though I have plenty of RAM
> free. I'm guessing that it's because my python is only 32-bit?

If you do use a 32-bit python, then yes, that's the reason.

> Appreciate any pointers on how to get my app to be capable of using
> the full amount of RAM. I'm anticipating this may require me to
> rebuild python from scratch for 64bits but I can't find instructions
> on how to do that.

As a starting point, you need to install a 64-bit operating system.
If you are running a 32-bit kernel, then there is *no way* that you
could possibly run a 64-bit Python on it.

When you do install a 64-bit (i.e. AMD64) version of Ubuntu, it will
come with a 64-bit Python executable, so no need to build Python at
all. If you still wish to rebuild Python, then, on the 64-bit Ubuntu,
the standard configure;make;make install will do the trick.

Regards,
Martin