try virtio-scsi and virtio-net for better performance
args: -device 'qemu-xhci,addr=0x18' -drive 'id=synoboot,file=/var/lib/vz/images/redpill-DS3615xs_7.0-41222_b1629030772.imgif=none,format=raw' -device 'usb-storage,id=synoboot,drive=synoboot,bootindex=5'
balloon: 0
boot: cdn
bootdisk: sata0
cores: 6
cpu: host
hookscript: local:snippets/exec-cmds
machine: q35
memory: 16384
name: DS3615xs
net0: virtio=00:11:32:xx:xx:xx,bridge=vmbr0
numa: 0
onboot: 1
ostype: l26
scsi0: lvm-gen8:vm-210-disk-1,discard=on,size=256G,serial=data,ssd=1
scsihw: virtio-scsi-pci
serial0: socket
serial1: socket
serial2: socket
sockets: 1
tablet: 0
vga: serial0