That trick with systemd-nspawn is not swapping the real 32-bit installation on USB-stick, it is just a container like Docker.How do I swap user space to 64 bit ? I don't understand this partYou could maybe try to run the rootfs on SD-card as container, so mount is somewhere and then:
sudo systemd-nspawn -bD <mountpoint>
You need to re-install basically, you cannot upgrade a 32-bit userspace to 64-bit userspace. So means backup your own changes to 32-bit rootfs and overwrite it with 64-bit rootfs and then re-do changes manually. What makes sense depends on how much changes you did and also if you all known them.
I have added a 3rd partition to SD-card for my RPi3/4 with 64-bit rootfs (was Buster at that time). Then step by step copied things over from 32-bit to 64-bit. Was multi-year period of time as cameras and and displays etc weren't working in 64-bit at that time. So I basically manipulated config.txt and cmdline.txt before every reboot to swap booting between the 2 until in bookworm or so the 64-bit was simply better than 32-bit.
If you want continuous service of your 32-bit userspace, as indicated, you can run it as a container in 64-bit. Or more extreme and flexible I do for decades also on x86 PC, make the 32-bit a virtual machine and run that on the 64-bit host. Does not work out-of-the-box on RPi as you need to fetch a standard Debian armhf kernel from (additional) Debian repo or so. Also only works for pure SW, no camera GPIO things etc.
Statistics: Posted by redvli — Sat Jan 03, 2026 1:27 pm