In-service configuration upgrade using virtual machine instances

摘要

Techniques described in this disclosure relate to configuration updates, such as performing an in-service software upgrade on a device, using virtual machines. In a routing device, a routing engine utilizes a virtual machine executing on a hypervisor to provide control plane functions. In one example, an in-service software upgrade may be performed between a first virtual machine and a second virtual machine without a managing virtual machine. More specifically, a first virtual machine in the control plane of the router may control the upgrade process, including requesting initialization of the second virtual machine, installing a new software system on the second virtual machine, and replicating state data from the first virtual machine to the second virtual machine. In this example, the first virtual machine may operate as a master virtual machine and the second virtual machine may operate as a slave virtual machine that synchronizes with the master virtual machine.

主权项

1. A method comprising:
a routing component of a network device, running a first virtual machine executing a first operating system that controls a routing communication session between the network device and a second network device, and controls an in-service configuration update (ISCU) of the routing component; in response to receiving an ISCU request with the first virtual machine to update the first operating system for the routing component, initializing a second virtual machine on the routing component of the network device; installing a second operating system on the second virtual machine running on the routing component of the network device, wherein the second operating system is different than the first operating system; transferring control of the routing communication session from the first operating system on the first virtual machine to the second operating system on the second virtual machine running on the routing component of the network device while continuing to forward data packets from the network device to the second network device; and after transferring control of the routing communication session to the second operating system on the second virtual machine, shutting down the first virtual machine.