Whenever you get storage masked to your esxi node/cluster you always going to need to know what HBA WWN addresses are (assuming your using HBA not iSCSI etc) here is a quick powercli hba statement you can use to refresh your memory

 

For a cluster the following:

1
Get-Cluster clustername | Get-VMhost | Get-VMHostHBA -Type FibreChannel | Select VMHost,Device,@{N="WWN";E={"{0:X}" -f $_.PortWorldWideName}} | Sort VMhost,Device

 

And if you want to do a single host:

1
Get-VMhost -Name hostname| Get-VMHostHBA -Type FibreChannel | Select VMHost,Device,@{N="WWN";E={"{0:X}" -f $_.PortWorldWideName}} | Sort VMhost,Device