Starting with Cisco NX-OS Release 5.2(1), multiple linecards can be simultaneously upgraded, and the infrastructure support is available. This decreases the ISSU time when compared with an ISSU upgrade that is done serially (one card at a time). To start a parallel upgrade, use the following command: install all kickstart image system image parallel. Reference: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus7000/sw/upgrade/guide/cisco_n exus7000_software_upgrade_and_downgrade_guide_8x.html