Some time ago, the following problem occurred with the SC7020F
One of the controllers stopped responding via IP. However, FC traffic continued to flow.
It was decided to reboot this controller.
After the reboot, half of the volumes became unavailable on all hosts (These were the volumes for which this controller was the owner).

The problem was solved only by rebooting the hosts. Reset HBA did not help. I had to reboot all the hosts.

I would like to understand what the problem could be. We assume the following reasons:

1. Perhaps, when rebooting the controller, the owner change mechanism did not work correctly.

2. The wrong driver was selected during the ESXi update.

It was version 14.0.169.25-5vmw, now updated to 14.0.169.26-5vmw.

3. Port zoning is currently configured. Can you tell me if the SC7020 supports port zoning, or is it necessary to configure WWPN zoning?

The controller has not been rebooted since then. Now a reboot is required and we would like to take the necessary steps to prevent the problem.