Shared network attached storage - trunked with multiple vlans?

cn flag

I am introducing an NFS server which I would like to share with KVM guests across different VLANS. I am trying to find a solution which would strike a good balance between function, serviceability, observability, and security. In this case I have three KVM-Hosts which are configured as follows:

  1. Bond created for physical NICs on the KVM-Hosts (4x 1GB on each)
  2. Interfaces "vlanX" created for each vlan on all KVM-Hosts
  3. Bridges "brX" created for each "vlanX" interface.
  4. Machines are all connected to the same switch (Layer 2)
  5. Router has a single GB link to switch trunking all VLANS.

VLAN Membership based on hostname:

KVM1-Host: br10
KVM1-Guests: br20, br30, br40
KVM2-Host: br10
KVM2-Guests: br20, br30, br40
KVM3-Host: br10
KVM3-Guests: br20, br30, br40

Host Membership based on VLAN:

VLAN10: KVM1-Host, KVM2-Host, KVM3-Host
VLAN20: KVM1-Guests, KVM2-Guests, KVM3-Guests
VLAN30: KVM1-Guests, KVM2-Guests, KVM3-Guests
VLAN40: KVM1-Guests, KVM2-Guests, KVM3-Guests

My thoughts where to put the NAS:

  1. Place the NAS on VLAN10
  • not really thrilled about having the NAS on a host management vlan.
  1. Create a separate VLAN for NAS
  • Seems like an easy way to isolate the resource - existing monitoring would easily be able to observe resource usage - however - this would require the overhead of routing to and from each VLAN.
  1. Add the NAS to VLAN 20, 30, 40
  • Guests can communicate with nas on the same vlan - less network overhead? I think I should validate this assumption with testing.
  1. Combination of 2 & 3.
  • NAS would be accessible by resources not in VLAN20,30,40 on VLANX
  • Guests can communicate with NAS on their own VLAN.

Please let me know your thoughts! I am still cutting my teeth in this area coming from a programming/dev background.

au flag

I'm not exactly an expert in this area, but I know using multiple interfaces to directly connect a NAS to multiple VLANs happens out in the industry (courtesy of the occasional mention from Lawrence Systems on YouTube). You can use the NAS firewall and/or listening addresses to control access to the NAS in a vlan-specific way if you go that route.

I'm sort of partial to putting the NAS in its own VLAN, though. You gain the ability to firewall at the network, not just the NAS itself, and I haven't seen inter-VLAN Routing be a major issue (mostly from lack of experience). But, I don't know if this is a common approach out in the industry.


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