Legacy .bin files allowed routing protocol processes (OSPF, IS-IS) to consume up to 95% CPU. The QCOW2 overlay enforces a cgroup limit, capping control-plane CPU at 75% during route flapping. This keeps SSH and SNMP responsive.
This article explores the specific software image , a widely used virtual image for the Huawei NE40E Universal Service Router . ne40ev800r011c00spc607b607qcow2 better