Home > Storage > PowerScale (Isilon) > Product Documentation > Management and Migration > Dell PowerScale: Non-Disruptive Upgrade Best Practices > Patch upgrade
The OneFS patch system provides a method to deploy a set of changes to all nodes in the PowerScale cluster in a simple and revisable manner, which is also under the control of the OneFS NDU framework. It allows a user to apply a patch in a simultaneous way or a rolling sequence. The details of rolling and simultaneous patch upgrade are shown in the section Rolling and simultaneous patch upgrade.