I like putting old and capable hardware to good use if I can help it. Sometimes it doesn’t make sense (like in the power consumption department, which is why I am a huge fan of low-powered stuff and why I have 2x AsRock J3455Ms and lots of RPis). I used to have my PC with a Pentium G4560 (a mere dual core with hyperthreading and 8 GB of RAM) run Manjaro as host and Windows with GPU, SSD and PCI-E Card to USB, all passthrough’ed. But I realized that having such low specs and low power consumption, it’s better to split my PCs. That one is running Windows (I have no idea why it is even powered on anymore, I only play DOOM mods on it). My main PC (which I’m typing on) runs on one of the J3455Ms (still in the process to move full time on a Pi 4 8gb), the other one runs pfSense.
What does the above mean? Well, if you have an old system and you want to run both Linux and Windows at the same time… then don’t, just get a newer-ish PC (something like a Dell Optiplex 3020 or 7020) and run Windows on that and keep Linux on your older boxes and downsize your resource requirements as much as possible (needs some relearning to do stuff and get into minimalist Linux setups). Or if you really can afford, just get rid of everything and get an 8 core Threadripper 1900X (they’re pretty cheap these days if you can find them) or Ryzen 1800/X or even a 6 core variant like 2600 or 1600AF and split that into VMs. A rack server only makes sense if you have a rack and a place for it where you can’t hear it. I’m running an Intel Server Board with a Xeon x3440 inside an old Antec desktop case with 24 GB of RAM. It is pretty quiet (compared to my HP 48 port switch), but I’m insane and sleep near jet engine sounds (would not recommend). Or if you really want ECC (which is why I have this old Xeon in the first place, I took it from work, because we wouldn’t keep a desktop case in the data center where we moved).
There are so many things you could do, really, just depends on your preferences. Keep old stuff and “decentralize,” buy one new big bulky server and remove (almost) everything else, buy a decent PC and keep some of the old stuff, make a cluster at home, idk… You still haven’t told us your use case.
If you really like spinning VMs up, if I was you I’d get 2 mediocre spec’ed PCs, one for Windows and one to run Proxmox or Xcp-ng on it and spin VMs and containers on. What I have right now is:
- LackRack and 3x 2U chassis with PC components and one empty 2U one (can’t use it at all), out of which are:
- pfSense box (always on)
- main (Linux) PC (always on)
- an old Athlon x2 4450e running Windows 8.1 (haven’t powered it since probably October last year or earlier
(the above 3 are rack mounted)
- ProxmoxVE box (tower PC case, but server components, always on)
- windows 10 box (SFF PC, always on)
- Pi 2 being a jump server (through SSH) from WiFi VLAN to my other LANs (always on)
- Pi 3 (haven’t powered it on in a while, currently OS-less)
- Pi 4 (trying to move to it, I’m really close, always on)
- Windows laptop, only using it rarely, when WFH (always off)
- 8 inches Windows tablet (used to be always off, updated it and will try to move my work activity to it and gift my laptop to my mom, because her kinda broke).
I got too many devices. I was thinking to make a cluster out of my main racked PC and the SFF one, together with the server and run HA and replication on my most important stuff. Was thinking to make the Pis run micro-services inside LXD, but not sure what I would run on them that my cluster won’t be able to handle (and do it with some level of redundancy).