Upgrade a 32 bit Debian install to 64 bit
 

I was wondering if anyone had any experience with converting a 32 bit Debian install to a 64 bit one.

This is on a server at work, and I cannot afford too much downtime. When installing before, I was incorrectly informed of the machine's specs. I know that I should have done more investigating, but hindsight is 20/20.

The 32 bit version is running okay, but I am running into an issue where I really need the 64 bit stuff installed.

This server is running Apache 2.2, MySQL 5, PHP 5, and Bind.

Are there any pitfalls I should be wary of? Is there any advice that one could give me in this instance? I really would prefer to avoid a total reinstall but will do so if necessary.

Thanks for any help!

Though I don't use 64-bit machines myself (for the desktop use they still have too much trouble, non-working software/programs lacking 64-bit support, ...), I don't think you should (or if it's even possible) try to "upgrade it to 64-bit". Even if that was possible, I'm sure the downtime is much longer than if you just did a clean install. You have backups, or should if it's a server, but make as recent ones as you can, copy your server's configuration files to a safe place and do a fresh install. Or better yet, you should have an identical machine for testing (production machines should have a "clone" test machine, on which upgrades can be tested before hurting the main machine) and do the install on that first and see if it even helps. I don't recommend upgrading a working server from 32-bit OS to 64, unless it is really really really needed. Don't fix a working thing. What is it that doesn't work without a 64-bit OS?

Just a friendly advice, if you insist on upgrading the system, and especially if you insist on doing that without a complete clean reinstall (formatting etc.), you are going to trash the server and have a very long downtime fixing it.

EDIT: unless, of course, you're very good in it - but if you were, you probably wouldn't be asking. So I assume you haven't done it before, and therefore should try to stick with methods that work.

There is no upgrade path from 32 to 64 bits it needs a re-install you can use dpkg --get-selections > packages.txt on the old machine to get the packages installed then once on the new install dpkg --set-selections < packages.txt to set them for upgrade then apt-get dselect-upgrade to have them installed and of course if you have backed up your /etc/ and /var directories you should be able to restore them to get the config files and data installed on the new machine.

@b0uncer
The software that is not working is a proprietary piece from AcuCorp (yes - a provider of COBOL :rolleyes:) that allows database-style access to data files on another server. This software is pre-compiled for a specific architecture and glibc version. I have been running into a couple of other issues, also.

Everything is backed up.

*cracks knuckles*

Time to get down and dirty and relay the news to the boss when I get back from vacation.

Thanks for the help guys/gals!