Maybe Syncthing is the way forward. I use it for years and am reasonably comfortable with it. When it works, it works. Problems is that when it doesn’t work, it’s hard to solve or even to know about. For the present use case it would involve making a lot of shares and manually toggling them on and off all the time. And would need to have some kind of error checking system also to avoid deleting unsynced files.
Others have also suggested NFS but I am having a difficult time finding basic info about what it is and what I can expect. How is it different than using SSHFS mounted? Assuming I continue limping along on my existing hardware, do you think it can do any of the local caching type stuff I was hoping for?
Re the hardware, thanks for the feedback! I am only recently learning about this side of computing. Am not a gamer and usually have had laptops, so never got too much into the hardware.
I have actually 2 desktops, both 10+ years old. 1 is a macmini so there is no chance of getting the storage properly installed. I believe the CPU is better and it has more RAM because it was upgraded when it was my main machine. The other is a “small” tower (about 14") picked up cheaply to learn about PCs. Has not been upgraded at all other than SSD for the system drive. Both running debian now.
In another comment I ran iperf3 Laptop (wifi) —> Desktop (ethernet) which was about 80-90MBits/s. Whereas Desktop —> OtherDesktop was in the 900-950 MBits/s range. So I think I can say the networking is fine enough when it’s all ethernet.
One thing I wasn’t expecting from the tower is that it only supports 2x internal HDDs. I was hoping to get all the loose USB devices inside the box, like you suggest. It didn’t occur to me that I could only get the system drive + one extra. I don’t know if that’s common? Or if there is some way to expand the capacity? There isn’t too much room inside the box but if there was a way to add trays, most of them could fit inside with a bit of air between them.
This is the kind of pitfall I wanted to learn about when I bought this machine so I guess it’s doing its job. :)
Efforts to research what I would like to have instead have led me to be quite overwhelmed. I find a lot of people online who have way more time and resources to devote than I do, who want really high performance. I always just want “good enough”. If I followed the advice I found online I would end up with a PC costing more than everything else I own in the world put together.
As far as I can tell, the solution for the miniPC type device is to buy an external drive holder rack. Do you agree? They are sooo expensive though, like $200-300 for basically a box. I don’t understand why they cost so much.