How to move root to usb stick?

I’ve been running Volumio 1.55 on a RaspberryPi B+ for two years (if it ain’t broke, why fix it?) but due to other changes in my system have just updated to Volumio 2. But I can’t find the guide I used back then to shift the root file system to a usb stick, to save thrashing the micro sd card. I found this: … lash-drive
but it’s very old and didn’t work for me because I couldn’t find the crucial <root= …> in the cmdline.txt file in the boot partition! I wondered about this: … 29&t=44177
but it seems quite involved and again no guarantee it will work for Volumio.

So, can some kind person point me to a straightforward guide to booting Volumio 2 from a micro sd card to a usb stick for the main file system? I’ve done quite a bit of searching, and surprised to have found nothing very usable so far.

Should be possible now under Berryboot, but not tested yet (nor officially supported).

this is a heavy read…

is there a possibility to just move out the important parts to a usb-hd? i now have a usb-hd connected on which i placed a large swap file (etc/fstab). now I could move large portions of volumio out.

Yes, and it probably took much more of my time to explain things in details than it will take users’ to read through it: length does not mean complexity actually (only 6 install steps).
Since it is not a supported method, I wanted to make sure users are properly aware of important things, and do not scratch their heads too much through trials & errors (and many repeated Q&A).

Very unlikely: Volumio uses it’s own initramfs which has no idea about your USB disk, nor how/when/where to mount it as rootfs, etc…
But your call…good luck!