Making FC Zone Changes on Nexus 5500 Series

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I am fairly new to the world of FibreChannel, and recently discovered a gotcha when making changes to zoning configuration for one or more zones which are part of the active zoneset, which I will share with you now.

A Cisco Nexus 5548UP (Unified Ports)

Updating the zone configuration

Below is a sample zone configuration for a Nexus switch, and we can see that we have two WWN’s in a zone, the zone is part of a zoneset, and that that zoneset has been activated.

zone name MY_ZONE_NAME vsan 101
    member pwwn xx:xx:xx:xx:xx:xx:xx:xx
    member pwwn yy:yy:yy:yy:yy:yy:yy:yy

zoneset name MY_ZONESET_NAME vsan 101
    member MY_ZONE_NAME

zoneset activate name MY_ZONESET_NAME vsan 101

Now, suppose that you make a change to that zone, or add another zone to the same zoneset; although the zoneset is already ‘active’, your changes wont be applied.

In order for our changes to be applied, we must re-activate the zoneset which, at first glance sounds like a disruptive operation. The zoneset activate command is part of the running configuration, and to disable and re-apply such config items we typically negate the command (no zoneset activate…) first and then re-apply it.

In this situation simply re-issuing the same command which is already in your running configuration will update the active zoneset in a non disruptive fashion. In my case I needed to configure zoning for a new server (Running ESXi) which needed access to VMWare datastores on the SAN.

I hope this helps somebody out as although I thought it must be possible to add new zones without causing downtime it was unclear at first.