Home > Storage > PowerScale (Isilon) > Product Documentation > Data Protection > High Availability and Data Protection with Dell PowerScale Scale-Out NAS > Parallel upgrades
OneFS 8.2.2 and later versions offer parallel upgrades, whereby clusters can upgrade an entire neighborhood, or fault domain, at a time, substantially reducing the duration of large cluster upgrades. Also, OneFS 9.2 and later versions combine operating system and firmware upgrades, substantially reducing the impact and duration of upgrades by allowing them to occur in tandem. Version 9.2 and later also include drain-based upgrades, whereby nodes are prevented from rebooting or restarting protocol services until all SMB clients have disconnected from the node.
SMB client connection draining can also be managed at the node level during an upgrade through the WebUI Upgrade status page.