To reduce disruptions during a major software upgrade on a Cisco Nexus Series switch, technologies like VDC (Virtual Device Contexts) and vPC (Virtual Port Channels) can be implemented. VDC allows for the partitioning of a single physical device into multiple logical devices, which can be managed and operated independently. This means that one VDC can be upgraded while others remain operational, minimizing downtime. vPC enables the linking of two switches to create a single logical switch, providing redundancy and allowing for one switch to be upgraded while the other maintains the network operations1.