Hello everyone,
I'm in dire need of some guidance, and because time is of the essence, I'm forced to ask first and rummage second. There's a lot to digest here, so I'll dive right in:
The situation:
My partner is an Elementary School educator. Last year, I set her up with a 3B+ based system so that she can perform certain web based tasks from home instead of at her school. We quickly found out that Ubuntu MATE (18.04) works for her, whereas Raspbian did not ( NOTE: It's not due to a software issue! ).
Fast forward to late February, 2020: We got word that if her district will need to close due to the Covid-19 outbreak, everything will move online and, in addition to the district's web-based administrative tools, Class Dojo and Zoom will be the de-facto platforms for her grade levels. Both of these work well on the Pi, although you can't drag and drop in Class Dojo (thankfully, "Browse" works! 
). They would then go on to add Google Drive for document sharing between educators to the mix. Again, no problem.
Skip ahead to March: School is closed and Distance learning is in progress. The Pi purrs happily 95% of the time. That 5% when it doesn't, is because I/O Wait is going through the roof. That locks the Pi and can only be fixed with a reboot (ouch). It turned out that this was due to a combination of concurrently running tools, too many tabs open in the browser (Chromium), or resource-intensive scripting on certain web sites. In other words, a balancing act.
Then they added SimpleK-12 as a requirement for educators; the site offers video-based seminars. This web based platform dropped reliability to 90%. The only way to prevent the I/O Wait induced lock is for Chromium to be the only thing running, and that site the only one open. That's because there's a LOT of scripting, animation, and other resource-intensive stuff on the site to plow through. They also added Google Classroom, which prompted her team to use collaborative editing in Google Docs for lesson plan development. It's brought reliability down to 80% and that's becoming a problem.
Today she was told that from the week of 20 April, they will be moving to a Google Screen-casting platform. I know I can add a camera to the Pi so she can do video conferencing; that's not an issue. We're going to test the screen-cast platform on the Pi later today, but I'm starting to run out of solutions to try for fixing the reliability bit...
Where I need input/help:
- I've thought of adding a swap partition because Ubuntu MATE (at least) does not set one up. Aside from knowing better, I've read countless warnings about swap files on flash media (i.e. don't do it because of R/W wear), so that's out. Instead, I've thought of a USB HDD to use for swap. But I've also read that this isn't wise on account of USB transfer speeds (the power draw is fixable with either a self-powered HDD or a powered hub).
- Another thought I've had is based on using a RAM-Disk, namely setting one up and using it as a swap partition. However, I don't know that it's prudent with the 1Gb of RAM on the 3B+. And that's after the question of whether that's even possible (it is, unfortunately, beyond my comfort level to go at solo; I know my limits... LOL!)
- Which brings me to the final thought: Upgrading her machine to a Pi4. If so, should it be a 2 or 4Gb variant? I would think that 4Gb will be better (see RAM Disk notion, above), and yet...
Please note that I'm going on the assumption that the Pi is running out of resources. I'm open to the possibility that I'm in the wrong rabbit hole here! It might be as simple a fix as changing a setting in the config file,etc. Quite simply: I. Don't. Know. That's where I need as much help and advice as I can possibly get. Coming back to my initial statement about available time: My partner needs to report her readiness status by 15:00 ET tomorrow (8 April). Any hardware purchases must take into account shipping times (slowed because of the Covid-19 crisis), as well as time for setting up, testing, and tweaking, not to mention the 20 April start date.
No, the district won't issue her a laptop at this time, and even if they were to, she cannot use one for the same underlying reason that the Raspbian UI doesn't work for her.
Thank you in advance!