I've been using 32 bit Ubuntu for the last couple of years on my development machine.
I generally write web apps in php.
I would like to use a 64 bit OS for the obvious reasons but wonder if there are any Got-Ya's that I should know about.
For those that are using a 64 bit version of Ubuntu, is it as straight forward as using the 32 bit version, or are there issues that one needs to be aware of?
Definitely go 64bit. Debian and Ubuntu have good compatibility solutions for 32-bit stuff these days, and since it's they provide free software in a huge repository of applications compiled for your 64-bit version, you're just about in the best place you can be to have optimised software for your 64-bit hardware. Highly recommended.
A few releases ago, there were a variety of weirdnesses.
I haven't seen any that have affected me since 8.04, though.
One day I noticed that my CPU is actually 64-bit :) that was kinda surprise. I immediately downloaded KUbuntu Jaunty (9.04) 64-bit, and everything worked just fine without any 'but's ;)
I'm also a web/php developer. All the tools are okay. You can even copy the whole /home/$(whoami) directory and all the settings will be preserved.
Switch! You'll get faster floating-point operations (i'm sure you play Nexuiz ;) as the bare minimum: double data type has 64 bits, and on 32-bit systems it's processed twice slower that on 64-bit systems, where the whole double can be transferred once :)
Check graphic drivers compatibilities (especially if you are planning on using the ATI / NVidia closed source packages) or any other closed source drivers / software you may use.
Apart from that, most things should be fine.
I tried 64 bit with 8.04. There were terrible problems with triangle of Web applications, Java and Firefox. Some folks said they fixed it, I tried all the fixes and never could get a Java app to launch from Firefox (64 or 32 bit firefox and/or Java). Meanwhile I had no problems with 32 bit 8.04 on another system.
Maybe this is all fixed, or was all fixed, or maybe there was an issue with my very early 64 bit hardware (socket 754), or maybe me. I've been running 64 bit Linux Red Hat servers for 5 years now with no problems running 32 bit java apps under Firefox. It was enough that when I updated to 9.04 on that system I went back to 32 bit.
Hopefully this issue has been fixed, and by fixed, I do not mean an elaborate work-around as published for 8.04 64bit, but fixed on install.
I would not hesitate to use 64bit for a server.
Make sure ia32-libs is installed and you should be all set. ;)
Most of the issues that were plaguing 64 bit linux installs have been resolved for the most part, however if you are looking for a performance boost you will not find it by moving to a 64bit userland. Unless there are specific applications you use which you think would benefit from more addressable ram, or 64bit copy operations / addressing, I would recommend sticking with 32bit. The much advertised advantes of 64bit software are mostly skin deep now, even years later.
First, make a list of all applications that are important for you. Second, check if any are closed source. Last, ask in here or google those applications for 64 bit ubuntu support.
Most/all free software works excellent in Ubuntu 9.10 64 bit.
