VMs considerably slower after migrating to new hardware and from proxmox 4.x to 8.2

[Hfuhruhurr]

Hi all,

I recently set up a new machine for proxmox with current hardware (old one was from 2016), a lot more processing power and installed proxmox 8.2
After moving the VMs to the new machine, I found that e.g. the odoo ERP was about 10x slower and also a redmine instance is noticebly slowed down.
I fixed one of them (odoo ERP) by turning the VM into an LXC container but am reluctant to do this for the other machines as well.
Is there a general explanation and, if better, a solution which speeds up the machines?

Edit: both, the old an new server use an SSD for the base system (lvm) and two magnetic disks in RAID1 for the VMs and their disks with ZFS.

Here as an example the configuration of a machine that has definitely become a lot slower in the new system:

balloon: 512
bootdisk: sata0
cores: 2
ide2: none,media=cdrom
kvm: 0
memory: 2048
name: Redmine
net0: e1000=F2:60:08:04:62:F4,bridge=vmbr0
numa: 0
onboot: 1
ostype: l26
sata0: RAID_ARRAY:vm-111-disk-0,cache=writethrough,size=100G
scsihw: virtio-scsi-pci
smbios1: uuid=aa05626f-508e-4414-9ebe-89495160cc51
sockets: 1

Best regards,

Rainer

 

[VictorSTS]

kvm: 0

Seems you have KVM acceleration disabled in that VM, so the guest OS has to be fully emulated by software, which is way slower than with hardware assistance.
Also, the disk should be scsi connected to a virtio-scsi-single controller and network card should be virtio too for best performance. I would also disable balloon by setting the same value for memory and minimum memory.

 

[Hfuhruhurr]

Oh dear!
You're absolutely right. Virtualization was not activated in BIOS.
Activated it, changed all interfaces on all machines to virtio.
Thanks so much. Warp 5

Best regards,

Rainer