@nvs said in XCP-NG server crashes/reboots unexpectedly: Thanks. Unfortunately my machine doesnt have IPMI. So can I just connect a serial cable between this machine and another machine Yes though you would still need to boot using the "XCP-ng (Serial)" grub entry. (you can also add some serial console bits adding them to xen cmdline)

@yzgulec as people have rightly said above, no hard and fast rule. But when it comes to sizing compute for mixed workloads (or unknown workloads) I have used a 1:4 (pCPU:vCPU) contention ratio. I also try and size 2GB of memory per vCPU (so 8GB RAM per pCPU), and with this 'rough guide' I find that my CPU and memory consumption scale nicely. Obviously it gets difficult when someone has a workload that needs very low CPU but high memory (e.g. I've seen a 2-core VM with 64GB memory) and conversely high CPU and low relative memory (e.g. 8-core VM with 4GB RAM)... but these are typically exceptions. Please share your decisions and build configs here, I'd be interested to see how it worked out in terms of compute:memory, costs, etc.

@joebeasley Mine is more of one or more VM will auto reboot and sometime one VM will be not be accessible (cannot ssh or console from XO) (CPU 99%, no network or disk activity as seen in XO and need to force reboot). After that a few hours later the Host will reboot. This is happening every day now. I am seeing a lot of this in the host dmesg. [105679.203854] vif vif-6-0 vif6.0: Guest Rx stalled [105689.395996] vif vif-6-0 vif6.0: Guest Rx ready [105707.532509] vif vif-6-0 vif6.0: Guest Rx stalled [105717.555832] vif vif-6-0 vif6.0: Guest Rx ready [105744.154415] vif vif-6-0 vif6.0: Guest Rx stalled [105754.163666] vif vif-6-0 vif6.0: Guest Rx ready

Hm that's important feedback thanks. We need to check if we can reproduce in here Ping @stormi so we can assign someone to test that

@manilx It is not cheaper, but it draws about half the power when idle. When doing work the power still gets up there, they are 60-90 watt computers, which is still less than the 300 watt capable HP servers at full go. If you really stress your lab a lot, real servers are a win as they will draw less power for more performance, but if yours is like mine and it idles a lot, cutting the power is nice. I'm about 200 watts at idle with the above, and that's two labs worth. I was 400 with the single old lab system. Mounts are cheap book ends, drilled and screwed to that specific shelf, and drilled for short m4 thumbscrews to get into the VESA mount on the t740. If anyone reading this wants to duplicate, and they see HP T755 cheap enough, I recommend these because it has 6 cores / 12 threads over the t740 with 4 cores / 8 threads. Both are DDR4 sodimm and top out at 64GB. Both have a PCI 3.0 x8 (x16 slot) that takes half height cards. And if the BIOS is locked, you can write over them with a programmer and enter the data needed to function (see badcaps forum for my guide).

@DustinB Excuse my ignorance, but I am not sure? I have two NVME drives with one being used by XCPNG/XOA. I was on xen and clicked the PCIE pass through on the host, restarted, and then black screen. I am trying to pass through the other NVME controller so I can have a truenas VM but utilizing the other NVME drive. I didn’t want one big pool because if something happens I’m not reformatting the entire thing and loose the data.

@davx8342 That's a ton of storage, holy cow! So two pools currently, 6 Servers 31TB Shared, and then 16 servers and 400TB Shared. I honestly don't know if there is an upper or lower limit to the amount of storage supported with XOStor, I'd imagine it would work but someone else would have to confirm.

@mohammadm said in XCP-ng 8.3 & AMD Firepro S7150x2: Too bad, so at this point we have 4/5 GPU's that are pretty much useless. Any other alternatives for GPU? When using dGPU, PCI-e passthrough to the VM itself, it does work but after a while the whole screen turn black. They have to disconnect and connect to the RDP session again to see the screen again. Looks like a screen suspend issue, have you tried to disable it ?

@deadman2141 I'm realizing what is happening. After the memory install the system would not boot up, the bios flags the change and forces you to go through the bios setup with a hardware change. My system runs headless so I did not pick this up. After plugging a monitor in I see that message, go into bios and then through the boot sequence. This is when I notice that the system "hangs" after that statement. What I just realized is that xo lite was responding (along with pings) while the system was hung. I pass the GPU to a VM, so once dom0 gets to a certain point the GPU goes away, leaving the monitor stuck, but the system boots just fine.

Are you on XCP-ng 8.2? Because UI to set passthrough is only possible on 8.3 up to date edit: 122 updates detected you really need to stay up to date

No problem

Ah nice catch! Happy to see it working now

@Andrew using the card in windows and using bootutil64e seems to have fix it.

Also, we might have better roles in the future to be sure other people without the right role couldn't use it.

@olivierlambert It ended up not being a resolution issue. We started having the same issue with a Windows-based server with a GUI. Our KVM is a Dell AV2108 (DAV2108) which is Dell-branded but manufactured by Vertiv (Avocent). Our console is a KMMLED185 which again is Dell-branded but manufactured by Vertiv. The KVM was on firmware version 02.02.00.00. After upgrading the firmware version to the most current, 02.08.05.00 and restarting the KVM, the issue was resolved. Hopefully this is able to assist another that encounters the same issue.

I had the same problem with a proxmox node that I'm using and the solution to this issue was solved by adding the serial port using the command qm set 102 --serial0 /dev/ttyS0. I thought that the same thing could be done here using xe or xl command; I just don't know how to achieve it in xcp-ng. The windows 11 vm shows a com1 port that has the same irq and i/o range numbers than the host; is this suppose to work?[image: 1738689956931-2025-02-04-13_13_16-windows-11-test-com-1-properties.png] [image: 1738689956968-2025-02-04-13_15_05-ret-xcpng1-ret-resource-pool-node.png]

@Andrew thanks for all your hard work. I guess time will tell if the Vates team has to add those defaults to their official package or maybe I just got "lucky"

@Shrubbery said in xcp-ng 8.3 not recognizing all host memory: The issue was memory reserved for the integrated graphics card haha.. that is such a silly thing... but good to know then next time I'm working on some hardware and wondering where the RAM is going too...

@scawtydont Thanks for keeping us posted. Dummy plug is still a thing it seems

If you are that much confident, then feel free to purchase one and use it: XCP-ng supports SRIOV but for NICs, I don't know how different it could be for a GPU, but without any hardware to test it's impossible to answer. How difficult it was to work on a more simpler hypervisor (KVM) doesn't send encouraging messages though.