just a short question regarding VLAN routing.
I host several VMs with several VLAN subnets including a virtual router for intervlan routing on one Proxmox server.
If a VM from VLAN10 would send data over to a VM on VLAN20 would those connection leave Proxmox to get to a switch or...
My fstab mounts work just with spaces but without tabs.
If it's a hardware RAID controller with no other usage then VM disks you might want to think about PVE built-in LVM-thin pools.
They do the mounting "magic" automatically.
Have you also checked the real iops on the server itself when your VM hangs?
In my opionion you are writing stuff to the RAM which needs to flushed to the storage after a period of time. Until the writing has been finished the IOs will be drastically reduced.
You may try to use the whole sysctl...