I've got several mac minis (Intel) - each is dedicated to a single client, and runs FileMaker server and Apache (and sometimes a few other minor services). I've been happy with this setup, but am planning a move to the M1s soon.
There are benefits to having separate hardware servers, but also risks as well, and I'm wondering if now might be the time to virtualize?
What if instead of running N separate M1 mac minis, I ran a single M1 (maxxed out with RAM/SSD) which ran several VMs inside it. I would probably run one VM per client, since I like to keep them very isolated from each other. I would run VMs of macOS (since that's what I know) but I suppose I could run Linux VMs if that made more sense.
Each client's workload is generally a monthly process, which tends to not overlap much in time (e.g. client 1's busy days are the 1st to 5th of the month, client 2's busy days are 10th to 15th, etc.)