Sorry i forgot to mention that i am on ZFS.
Found the soluition here: https://forum.proxmox.com/threads/disable-spectre-meltdown-mitigations.112553/
nano /etc/kernel/cmdfile
(change this line) root=ZFS=rpool/ROOT/pve-1 boot=zfs mitigations=off
proxmox-boot-tool refresh
reboot
Thanx everyone!