Storage traffic clarification.
I am probably missing something obvious but according to this article (https://www.shapeblue.com/understanding-cloudstacks-physical-networking-architecture/) by default primary and secondary storage traffic travels across the management network.
As an example assume basic networking with 2 NICS, one for management with an IP subnet, the other NIC for guest traffic using a different subnet. A physical host should only have one default gateway and this would have to be from the guest VM subnet.
I setup two tests -
1) the NFS server had an IP address from the management subnet
2) the NFS server was on a completely different IP subnet ie. not the management or the guest IP subnets.
Both worked but in test 2 I can't see how the storage traffic could be using the management NIC because there is no default gateway on the compute nodes for the management subnet and the NFS server is on a remote network.
So is storage traffic in test 2 actually running across the guest NIC ?
And as the recommendation is to have separate storage from guest traffic does this mean the NFS server has to be in the management subnet ?