How many cores do you really want for an XCP-NG home lab that will have a couple of VM’s “running” all the time?
I’ve been fooling with old X56xx series Xeons and have enough in my hot and loud machines at work to have 24 “cores” per host with 72GB of ram per host. I want to build something quiet and lower heat for home and before I buy more low power computers, I thought I should probably take the time to wrap my head around processor and ram provisioning in XCP-NG.
At work I’ve been building VM’s with 8 “cores” and 8GB of ram (hard maximums) to give me decent performance, but is this being wasteful? This would limit me to around 2 to 3 VM’s per machine without going too deep into over-provisioning. And certainly crunch things when I need to move VM’s to apply patches and reboot, etc.
What I’m really wondering is if I could get away with a few AMD 8c/16t (or smaller) computers, assuming I can pack a decent amount of RAM inside without costing too much. I mention AMD not because I’m a fan boy, but because I can get more cores per dollar (typically). Would 4c/8t or even 4c/4t really be enough for a domain controller (probably Zentyal), a couple Windows Server evals., and a couple Linux machines (per host)?
Decent low power computers can be had with 4c/4t and 8GB for around $200 each. An 8c16t computer with 64gb+ of ram is probably going to be close to $1000 each (new prices). I need to weigh not only cost/performance benefit but heat/power/noise, the last set stops me from just buying old servers and building a system on the cheap like I have stored at work (or bringing the system at work back home).
I’m currently doing things at home on Atom D525 and a couple dual core Celeron, the Celeron at least have 8GB where the Atoms are limit to 4GB and the Atoms run a bit hot since they tend to run above 50% processor all day long.
I’ve got a Lenovo i7 desktop which is running Proxmox, it has 14 vms running now 10 are headless Linux running various things, controller / mySQL / Wiki / fileserver and a couple of Linux desktops.
It does the job, I’ve installed 64GB of ram which is also shared between vms, but I don’t come close to maxing this out.
Basically the box and RAM cost £400 which is cheap, not sure if I was spending more I would get any benefit, perhaps power usage might be more efficient.
Though I would bet if you are running Windows vms this will demand more resources.
I would spend the money on RAM if budget is a constraint, though right now prices are all over the place.
I see some listings for this at 32GB max, and some at 64GB max. I’ll have to look around for older versions and see what I can find. Still trying to figure out what I can build for a decent Truenas for home, something like a mini ITX and 4 2.5 inch drives would probably be fine for what I’m doing.
I generally provision 2-4GB and 2 cores to my vms. Some are upped for things like Syncthing which gobbles up ram. Running vms headless is a massive saving in resources.
I like the idea of a desktop, 4 slots for full size ram, easy to add a quad port NIC card. When you go for the small form factors you quickly run into limitations. Though I have to admit I started off with a Lenovo m900 tiny, but lack of additional NICs was a problem.
Because electricity is included in our rent I had been using E5450’s for a long time and they were adequate for my needs still. However, the rack mount servers for this Gen are quite noisy and not so wife friendly considering she shares my office. So, I am actually moving to X55xx and X56xx Xeon’s currently. The tower ML150’s I find are decently quiet compared to the old E5450 systems. Unfortunately, HP never upgraded the BIOS to support the X56xx Xeon’s for that particular hardware (a Russian hacked BIOS does exist to add the support but that ain’t going on my hardware. lol) so I’ll also add a ML310/ML330/ML350 as well since I already have a couple X5670’s spare. The need for later CPU and tpm support for some Windows VM’s will probably be the only thing to get me to move hardware again any time soon. I run an Exchange 2013 VM for a few domains combined with Proxmox’s mail gateway and given there is less than a dozen users even the E5450 performs fine for that. As normal for Exchange, it just loves RAM.
