There is no way around this unfortunately.  You can't even switch to a DR cluster temporarily because that would be some downtime.
Hi Guys,  We want to upgrade a cluster from OneFS 6.5 to OneFS 7.0, a major code update. I have learned that only way to do this, is by doing a simultaneous upgrade, at end of which the whole cluster (all the nodes) will restart at the same time, which will take minimum 15 mins. We don't want any downtime, is there a way to do it without downtime?   Thanks, Gav
Upgrade to OneFS 7.0.1 from OneFS 6.5 without downtime, is it possible?