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As per title, I wish to know if I can, after a successful 32bit setup and consequent software installations, update to a 64bit version.

I know how to partition (actually one of the solutions is to set /, /etc, /home, /var/www, and /opt as separate partitions) and I know that a clean install is way better than a dirty one, yet I would like to know if/how it's possible to do that.

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This is the same question, but shouldn't be marked as a duplicate, cause there are alternative answers here also: How do I upgrade from x86 to x64 without losing settings? –  rubo77 Jun 20 at 7:51

8 Answers 8

up vote 52 down vote accepted

You will find a clean install a lot less hassle than any other unusual, obscure, unsupported method.

Your suggest of partitioning the config files, home directories, etc is probably the best idea, and it is possible to install the same packages on a clean install as on another install.

On the other hand, what you requested is possible, there is a little guide for Debian based systems but remember "this really is for professional-level sysadmins" and "this procedure is, in every possible respect, a bad idea. If it eats your firstborn, please don't come crying to me"... (so good luck)

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+1 to you. Not for the faint-of-heart... I was going to recommend backing up all config and data files that you care about (maybe even your apt logs), and doing a find-and-replace on your apt sources.list to point to the 64-bit versions. Then I read the tutorial mentioned and was quickly disabused of that notion... –  gWaldo Oct 1 '10 at 17:52
What if I have no firstborn, does this mean the procedure is safer for me than others? ..... i kid, the question is: If you just got 32 bit working right, why do you want to go through hell just to save yourself backup/restore of data time + reinstallation time, in the end this method is not faster. Faster = backup, reinstall. Also less problems in the long run. –  Dmitriy Likhten Oct 1 '10 at 18:48
Thanks a lot: eventually I backed up all my data, partitioned my disk and reinstalled. Now some hassle to restore DBs, webserver and some service is required, though. –  dag729 Oct 3 '10 at 8:54
@dag729: Trust me, its a hassle to backup/restore, but less than the alternative. You only do 32 -> 64 in dire cases. Even the sysadmins here at work won't do that, they backup, wipe, install, much cleaner/safer. –  Dmitriy Likhten Oct 13 '10 at 20:13

This might be a much more reasonable thing to do once the multiarch spec is implemented. https://wiki.ubuntu.com/MultiarchSpec -- currently postponed to 11.04, but keep in mind it's been postponed for about 6 releases now. That said, actual progress was made in 10.10, so maybe it'll happen this time.

Until then, don't bother. Backup your data, repartition if you want, and reinstall.

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Can't wait for the MultiArch to be implemented! –  dag729 Oct 3 '10 at 8:52
I believe 11.10 does use multiarch now. –  Christopher Kyle Horton Dec 21 '11 at 8:12

No you can not upgrade from 32 bit to 64 bit. It has to be a clean (fresh) install

Before you do make sure that your system is capable of a 64bit operating system, and check the minimum requirement for Ubuntu 64. You can do so Here

The terms 32-bit and 64-bit refer to the way a computer's CPU, handles information. The 64-bit version handles large amounts of RAM much better than a 32-bit system. If you are running a 32-bit version of Ubuntu, you can only perform an upgrade to another 32-bit version of Ubuntu. Similarly, if you are running a 64-bit version of Ubuntu, you can only perform an upgrade to another 64-bit version of Ubuntu.

If you want to move from 32-bit Ubuntu to a 64-bit Ubuntu, you'll need to back up your files, do a clean install of 64-bit Ubuntu.

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It is possible to upgrade ubuntu 32bit to 64bit, it will have lots and lots of unwanted files, and you have to clean it manually. Truth is "HEADACHE".


What ever you do, first back-up your important data. Then go for research with os.

First try live-cd of 64bit. If it works go for fresh install, recommended.

Also there are some software, which are still 32bit. So to install 32bit software on a 64bit os, we need some backward processing.. these will also a bad thing.

Think for some time : whats your requirement, what you are going to do, next plan/work with 64bit os.

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Your OS is still 32bit as you upgraded from a 32bit - see the answer in the comment for further information.

by the way is it possible for the coexistence of 32 bit Win and 64 bit Ubuntu?

Absolutely - it's called a dualboot - you would have the option at login to use either one.

Download and burn the 64 bit iso and boot with it, it will prompt you with various options - you would want to choose the Install alongside option.


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You can now do this fairly easily with recent installers (at least with 13.10 which I just used). Boot into the 64-bit image DVD (or USB drive or whatever) and choose the first option to reinstall, keeping your personal files. This works even if you don't have a separate /home partition.

This will reinstall most of the system including apps, but it takes a list of your installed packages beforehand to reinstall them from repo, so as long as a package has a 64-bit version available to it at the time, you should end up with most of your apps when you reboot. In my experience a few didn't get installed - mainly those that had been installed through 3rd party repos such as Google Chrome - but it doesn't take long to install these manually afterwards.

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You need to do a fresh install with the 64bit version of Ubuntu. It is possible to have 32bit windows and 64bit Ubuntu, as long as they are not sharing the same disk or partition, for obvious reasons. Refer to the documentation for howto on dual-booting.


It is important that the CPU on the machine you're installing onto supports 64bit instruction set (which most modern CPUs should by now)

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Sad news, breaking my happiness to have retrieved a fully working system after my old K7 MoBo died and I replaced it with a new A88 (FM2+) one. Some fstab tweaks later, I was logging in fine.

Now I feel sad I can't give my new processor a 64b OS. Re-setting everything would break my ass more than switching the MoBo, I'm sure everybody agree with that.

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This appears to be a personal comment rather than an answer to the question. –  Mark Stosberg yesterday

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