How disruptive is the hard drive firmware update? With controller firmware I recognize all connections basically get reset when the failover occurs but is the HD firmware more transparent?

Is 1500 iops too high to try and run the update?

Does the array update one drive at a time and then have to catch up and write any changes to disk that were missed during the update?

I'm trying to understand how things work so I can figure out if I need to plan an outage or can just run the update anytime.

Thanks