32->64 bit upgrade

[Sascha Wildner]

On 2/6/2011 6:10, Neil Booth wrote:
I have a 64-bit CPU but am currently running 32-bit dragonfly.
Is it possible to do a buildworld and buildkernel to upgrade to 64-bit
in-place?  Or does it necessitate a complete reinstall?
I'm concerned about e.g. the new 64-bit userland overwriting the 32-bit
one whilst still in use before installing and booting the 64-bit
kernel, etc.  I couldn't find anything about this topic on your webiste.
I think it's not easily possible to upgrade to 64 bit in place from a 
running system.

The easiest way I can think of is to boot a 64 bit LiveCD, mount all 
drives/partitions and copy stuff over manually.

Sascha