I’ve previously wrote a howto to upgrade your Isilon cluster’s firmware. The process hasn’t changed much over time: you upload a node firmware package to the cluster, install it, and then apply it to the nodes themselves. Time wise though, it’s not a quick process. Each node will reboot during this process, and the process takes at least 10 minutes per cycle. Imagine a 100+ node cluster and running this process one node at a time…
Fortunately, OneFS 8.2 has recently introduced a nice new tool to make this node firmware upgrade a bit easier and much faster: isi_upgrade_helper. It figures out which nodes can upgrade simultaneously and spits out the relevant commands for you.