Home > Storage > PowerScale (Isilon) > Product Documentation > Management and Migration > Dell PowerScale: Non-Disruptive Upgrade Best Practices > Fastest Firmware Upgrade Recommendation
This recommendation which is also known as simultaneous firmware upgrade is to ensure the data integrity during the firmware upgrade process by preventing any Gen 6 Node Pairs from being upgraded concurrently. For example, the simultaneous firmware upgrade will be run in the following sequence:
isi upgrade cluster firmware start --simultaneous --nodes-to-upgrade <odd number of slots>
isi upgrade cluster firmware start --simultaneous --nodes-to-upgrade <even number of slots>
Note: For Isilon Gen 4 or Gen 5 nodes which have no Node Pairs, you can add these nodes to either <odd number of slots> or <even number of slots>. By default, isi_upgrade_helper will add them to the <odd number of slots>.
It is not recommended to use this option to upgrade PowerScale node firmware in a production environment.