[SOLVED] separate nic for corosync?

[benoitc]

I know that ideally corosync has to run on distinct networks , especially when used with ceph. But I wonder if in practice if it's useful when you put the traffic of ceph in its own switch and other traffic on another? Ie.:

                         SWITCH 1
                         
                        |   |    |
node 1 NIC A -----------    |    |
       NIC B -------        |    |
                    |       |    |
node 2 NIC A -------|-------     |
       NIC B -------|----        |
                    |    |       |
node 3 NIC A -------|----|-------
       NIC B ----   |    |
                 |  |    |
               
                  SWITCH 2

What if i have 2 ringgs for corosync one on each switch? Each switch are connected with an active LAG of 2x10G For now I am using an USB adapter to add a nic to my system (I have "only" 2x10G) which I don't like that much.

 

[Dominic]

Yes, it is useful to separate storage network and corosync network. It is also useful to have different switches for different corosync links.

https://pve.proxmox.com/pve-docs/chapter-pvecm.html#pvecm_cluster_network_requirements

 

[benoitc]

Yes, it is useful to separate storage network and corosync network. It is also useful to have different switches for different corosync links.

https://pve.proxmox.com/pve-docs/chapter-pvecm.html#pvecm_cluster_network_requirements

but do you think i need to use this adapter? would it be okish if i have the initial corosync ring on the first switch and a backup ring on the second one mixed with the io traffic?

 

[Dominic]

Since lower priority links will not see traffic unless all higher priorities have failed, it becomes a useful strategy to specify even networks used for other tasks (VMs, storage, etc…) as low-priority links. If worst comes to worst, a higher-latency or more congested connection might be better than no connection at all.

https://pve.proxmox.com/pve-docs/chapter-pvecm.html#pvecm_redundancy

 

[benoitc]

ok thanks for the link. I will see hoz it goes