multiboot setup in a Raspberry pi

[fox]

I found a really good thread on this here. What made me interested in the topic is my attempt to run the pi OS from an external hard drive. In my case, there were supposed to be ways to automate the process, but none worked for me. I ended up having to install the Raspbian image from scratch on my SD card, follow a cookbook of terminal commands to clone the installation onto the drive and then I had to manually edit some boot-related files. But I don't think you could do this with a multi-boot setup from Noobs or BerryBoot; there isn't a grub or grub-equivalent to edit. Having read the thread, I think the easiest way to accomplish this and run from an external drive is to use a separate SD card for booting each different OS. It's a bit inconvenient if you bought the Creatron RPi translucent case (and maybe other cases) because you need a forceps or some other tool to remove the SD card.

My interest in doing this is to have a combination of a standard distro (Raspbian or Ubuntu Mate), LibreELEC, and Openmediavault on the same drive. Easy to do with Noobs if you run everything from the SD card, but having seen the speed difference between operating from the SD card vs an external drive, I think the latter is way to go. I would be interested to know if any of you see a better way to do this.

Incidentally, I think this may be a short-term problem, as there is already an experimental firmware update for the Pi (3 I think) that is supposed to allow it to boot from a usb medium. I applied the firmware but was still unable to succeed. However they do warn you that it is experimental and that it may not work with all usb devices. I only tried one.

[bobf]

I use the tip of a nail file to shove the microSD card back out of the slot; a YouTube vlogger suggested a small piece of cellophane tape folded in half and over the outboard edge of the microSD card as a "pull tab". I haven't bothered, YET, but I believe a number of cards, each specific to a purpose, is how I'll eventually proceed, unless I decide on a particular application long-term, eg., portable media server...

And I thought the Pi 3B would already boot from USB, but I hadn't really followed up on the process, while still trying a whole bunch of different flavours first. I'd expect a USB flash drive to draw more power on startup than a microSD card, which is, in this case, very relevant...

[fox]

Interesting what a pi 3 can run at the same time without a powered usb hub or other power supply. I had attached to the pi a SD card, video cable, mouse, keyboard, usb pendrive and a usb HD. I was running Ubuntu Mate and copying files from the HD to the pendrive. None of this froze the pi.

[fox]

I have to say that Berryboot is a nice bootloader with some useful extra features. Not only can you add or remove OSes automatically through it menu editor, but also, you can add any OS that is packaged in the squashfs format that Berryboot needs. There are a bunch of distros already packaged that way from this website, as well as instructions on how to turn an RPi image file into a Berryboot image file that can be added through the menu. I tried packaging one myself (LibreELEC 8.0), but ran into problems. I'm going to request that the maintainer of the site package it. There is already a version 7.95.3 beta packaged, but maybe there were small changes upon its release as 8.0