Hotplug Support in PVE 8.04


Feb 12, 2021

We have the paid subscription of PVE, All nodes in the Cluster Updated using PVE Enterprise REPO.

pve-manager/8.0.4/d258a813cfa6b390 (running kernel: 6.2.16-18-pve)

I have given the number of cores as 16 and vCPU as 4, also enabled hotplug for Memory, CPU, Disk, Network and USB. Enabled NUMA, given cpu type as HOST. did everything. I can increase the vCPU count in proxmox but it does not change the CPU count in the VM, I have tried Win10, Win11, Win Server 2019, Win Server 2022 (All activated and Windows updates done too so, thats not a problem either). After reboot the increased vCPU show up in windows.

if i reduce the number of vCPU in proxmox i get the following error dialog box.

Parameter verification failed. (400)

vcpus: hotplug problem - 400 Parameter verification failed. vcpus: error unplugging cpu4

The - VM Config file is below
agent: 1
balloon: 4096
bios: ovmf
boot: order=virtio0;ide2;net0
cores: 16
cpu: host
efidisk0: CEPH:base-99993-disk-1/vm-105-disk-0,efitype=4m,pre-enrolled-keys=1,size=1M
hotplug: disk,network,usb,memory,cpu
ide2: local:iso/mouse.iso,media=cdrom,size=84K
machine: pc-q35-8.0
memory: 8192
meta: creation-qemu=8.0.2,ctime=1698046664
name: test-Win2022
net0: virtio=7A:C0:E4:28:C8:2E,bridge=vmbr0,firewall=1
numa: 1
ostype: win11
scsihw: virtio-scsi-single
smbios1: base64=1,family=UGVyZm9ybWFuY2U=,manufacturer=,product=SGlnaCBQZXJmb3JtYW5jZSBDbG91ZA==,sku=V2lu>
sockets: 1
tablet: 0
tpmstate0: CEPH:base-99993-disk-0/vm-105-disk-1,size=4M,version=v2.0
vcpus: 4
vga: qxl
virtio0: CEPH:base-99993-disk-2/vm-105-disk-2,discard=on,iothread=1,size=64G
vmgenid: f3eb1bb0-f10b-4fd7-8a34-18b11577e2be

the above article says that CPU and memory hotplug work on > 2008 enterprise/datacenter, 2012 > standard
But none seem to work, neither Server 2019 / 2022 nor win10 / win11. I did not try older OS.

Any ideas on this.


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