I'm trying to understand how to use fibre channel with OpenShift/Kubernetes persistent volumes.
At https://docs.openshift.com/enterprise/3.1/install_config/persistent_storage/persistent_storage_fibre_channel.html#provisioning-fibre it states that target WWN(s) must be specified, along with a LUN number.
I know WWNs, as these are readily availble in the SAN storage system and in operating systems (eg in output from "multipath -ll" on Linux). But I don't know how to find out which LUN number to write.
Apart from me not knowing where to get the LUN number from, I don't understand what Kubernetes needs that information for (I would like to try to understand that, too).