bjtheone wrote: ↑
Fri Aug 23, 2019 12:43 pm
The only use cases that have any show stopper level of need that I have seen are corporate/school environments...
Not wishing to add to the flames, so my post below is simply to set out the use case I have where USB boot on the RPi 4 would be of help to me. Quite happy to wait until it turns up, but there is a caveat to that: I have to hold off on buying RPi 4Bs for my classrooms until USB boot is available on the RPi 4B.
Why do I need USB boot from an external device without the need for a microSD card? If we were just starting with RPis for the first time, we wouldn't, but we have infrastructure around them already.
I teach Computing Science to pupils from age 11 up to age 18. We've been using RPis in classrooms for 2.5 years now. Initially we bought a couple of RPi 3Bs experimenting with microSD cards for each pupil.
In the classroom environment, we found the microSD cards to be problematic. No issues with reliability or performance, but they are so small that pilfering is potentially an issue, made worse by the fact that pupils often have smartphones which could use some extra storage--and a microSD card was perfect for that. MicroSDs are also very difficult to label, and impossibly easy to lose.
We also now maintain our own configured version of Raspbian, set up for our school with software we use, etc. Easily duplicated onto microSD, but the writing time is slow, and when one has 50+ to do, time does matter.
Since we wanted to allocate each pupil their own media device to hold their work, which they could use in any RPi in the classrooms, simply leaving microSD cards in the RPis wasn't possible.
Network storage might have been an answer -- had we been allowed by IT to attach a machine to the school network for that purpose. We weren't. So we went the external USB route, first trying USB flash drives (pen drives), but performance and reliability was dreadful. We then settled on to ultra-cheap and low-capacity SSDs connected via a SATA-USB cable. SSDs can be labelled, much harder to lose, are not really that much use to pupils (especially only 16Gb), and are both fast (especially to write our Raspbian variant), and reliable.
We added another set (22) of RPi 3B+, and they are in use in another classroom (less need to share the crate of RPis...).
In the future, we want more RPis, for at least one more classroom. The obvious choice now would be RPi 4Bs, but without the means of USB boot, these would not be interchangeable with the earlier RPis, and we would need both microSDs and SSDs to use them. The microSDs could just have /boot on them, and therefore not need to be taken out of the RPi 4Bs -- unless they "fall out", of course.
But going down the hybrid USB boot approach would require me to buy 66 microSD cards for all the RPis we have, since the other CS teachers are not going to be happy about doing things differently depending upon which RPis are inside the classroom they are using that lesson. Even at £3-4 each for a microSD card, in aggregate that's a sizeable sum for a school, and they would (hopefully) become redundant once USB boot is available for the RPi 4B. Once an established workflow is in place, amending it (or even improving it!) is always difficult to achieve.
Ours is a specialised use case, I would agree, but due to the circumstances I've set out, I can't see us being able to have RPi 4Bs in use in school for CS lessons quite yet.
So I'm not definitely NOT complaining, and I am happy to patiently wait for the developers to make USB boot availabe for the RPi 4B. But I thought setting out the issues we face at my school due to this temporary restriction might be of interest to someone.
On the plus side, I've now got our Raspbian version upgraded to Buster, with all the software we need (Scratch 3 desktop -- thank you!!!) and ready for use with our RPi 3B and 3B+, and one day soon this software will be on our new RPi 4Bs, too. RPis have been the best thing to happen for the teaching of CompSci for many a year; the pupils love them!