What s the difference between cluster networks and vm networ rancher-users #harvester

Title

little-dress-13576

02/28/2023, 6:12 PM

What’s the difference between ‘cluster networks’ and ‘vm networks’ in Harvester UI?

big-judge-33880

02/28/2023, 6:18 PM

vm networks

are used by VM network interfaces - vm networks are in turn attached to a

cluster network

(in practice a vlan-aware linux bridge) which is connected on each node to a

network config

(in practice a linux bond)

little-dress-13576

02/28/2023, 6:32 PM

Thanks! hmm, Say I need to add a new vm vlan 100 for new vms in this tagged vlan. I first created a new cluster network, naming it as

cvlan100

, then when I tried to create a new vm vlan

vmvlan100

, and trying to select

cvlan100

in the dropdown of

Cluster Network

, it only showing

mgmt

as a valid option, and cvlan403 is gray out, with

(Not Ready)

text near it. Is this expected?

just noticed there’s this ‘Create Network Config’ button in UI. But when I go to

Uplink

, it won’t show up the 2 NIC ports already being used for

mgmt

network (during initial installation), these 2 NICs were selected during initial installation. Does this mean it requiring lots of NIC ports, and each nic port could only be used for one vlan?

I have 3 nic ports for the physical hosts. 2 10g NIC ports, and one 1g NIC port. I used 2 10g NIC ports for initial installation, as bonding. Now it only showing this 1g NIC port as a possible selection when I try to create new vm vlan.

Does this mean I will have to keep using the default

mgmt

cluster network for all things later?

big-judge-33880

02/28/2023, 6:43 PM

the cluster network needs a network config, either targeting all nodes (if interfaces are identically named) or one for each node - this consumes the selected physical interfaces, just like the management bond consumed the two interfaces chosen for it

I’m not too familiar with all the different bonding modes - there might be one that lets you select just the single 1Gbit interface for a “bond”

little-dress-13576

02/28/2023, 6:45 PM

I don’t want to use the 1g port. Is it ok to share all things with default

mgmt

cluster network? any concerns in doing that other than it would get more traffic later? I assume

mgmt

should be able to support vlan tagging?

I think the main reason for cluster network use case if to get different physical network ports, and configure those to another vlan just for longhorn storage replication later.

big-judge-33880

02/28/2023, 6:46 PM

You can run everything over the mgmt bond “just fine”, but I think you’ll have issues with at least live migration (hopefully someone will correct me if I’m wrong)

little-dress-13576

02/28/2023, 6:49 PM

yeah makes sense. in VMware, we could have dedicated vmotion ip/vlan for live migration traffic separation, and decicated vsan ip/vlan for storage replication traffic separation .. I am not sure if possible to separate vmotion traffic in harvester case.

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