Migrating from 32bit to 64bit

[moody_mark]

Hi, Ive been using Ubuntu 32bit on my work Dell E6400 for nearly a year now with no problems. It is capable of running Ubuntu 64bit and Ive tried out the live CD which seems ok. I have a spare 40GB HDD and a USB caddy so Id like to install Ubuntu 64bit onto that and start working with that as a trial. Once im happy I can get all the usual things I need for my work (like vpnc) working then I'll wipe the main internal HDD and install Ubuntu 64bit.

Apart from backing up my home directory, id like to backup a list of my installed packages as a list of reference so I know what to add into my new install. Is there a "apt" command to do this and list the packages in a way where if I install those packages, I'll not hit any dependancy problems by installing one before another?

[wojox]

Run and post back:


sudo lshw | grep cpu

[moody_mark]

output:


*-cpu
bus info: cpu@0
capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx x86-64 constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm tpr_shadow vnmi flexpriority cpufreq
*-logicalcpu:0
*-logicalcpu:1

[wojox]

x86-64 yup, it will work. :p

[wojox]

I've never tried this from 32 to 64 bit but look here: http://stringofthoughts.wordpress.com/2009/04/29/package-installation-after-renew-install-ubuntu/

[moody_mark]

To quote the post above


To backup


sudo dpkg –get-selections > myPackages

To re-instate


sudo dpkg –set-selections < myPackages && sudo apt-get dselect-upgrade

This is a good tip, If using this technique is the order of the list important, will a dependency fail if the order is wrong? Also I wonder if when re-installing to 64-bit, would those packages be valid? Perhaps theres some other that are the 64-bit equivalent?

[bsharp]

Also I wonder if when re-installing to 64-bit, would those packages be valid? Perhaps theres some other that are the 64-bit equivalent?

That's a good point. However, Ubuntu has had 64-bit support since the beginning. I've been using it as long as I've been using Ubuntu (6.06). I haven't had any 64-bit related problems since at least 7.10, so unless you're using some very obscure packages, you will be fine. By now, even if you are using very obscure packages, you'll still probably be fine.

The only package I know of off the top of my head that wouldn't install would be w32codecs, to get it just install w64codecs. Any other problem packages would likely have a slightly different name.

Edit:You can also create/restore a list of installed packages through Synaptic.