The following procedure uses Isilon CLI commands to shut down the entire cluster.
Cluster Shutdown Procedure:
1. SSH connect to node1 of the cluster and log in as the root user.
2. From the command prompt, type the following commands in this order:
isi_for_array isi_flush
isi config
shutdown all
If a specific node does not power down follow these steps to shut it down:
1. SSH to the node.
2. Log in as root and type: shutdown -p now
DavidRing.ie 
Reblogged this on 50mu – about storage and commented:
Power down an entire Isilon cluster
Nice! We needed this a few weeks ago. We moved a cluster to another rack (on another floor) and we shut down the nodes one by one.
Thanks Rob, maybe next time 😀
Yeah. But I hope I never have to move an entire cluster again 😏