raw VMs

Raw VMs provide direct, unformatted disk image access to hardware resources without the overhead of specialized virtualization layers.

Raw VMs bypass the abstraction of formats like VMDK or QCOW2 by writing data bit-for-bit to a disk image. This approach maximizes I/O throughput for performance-critical workloads (like high-frequency trading or large-scale SQL databases) because the hypervisor performs zero metadata processing. Using tools like QEMU or KVM, operators gain precise control over hardware passthrough and storage alignment. While you lose features like live snapshots or thin provisioning, you gain predictable latency and a 1:1 mapping between the virtual disk and physical sectors.

https://www.qemu.org/docs/master/system/images.html