Cluster best practices

bellaireroad

Member
Sep 30, 2025
32
3
8
I have 4 machines I plan to cluster. I am going to put them on a seperate network. What happens to the IP of VMs/ containers (on DHCP) after they migrate? I am assuming if the VM or CT is on (for example) VMBR1 , it will use VMBR1 on the machine that it migrates to. Or is this incorrect?
Currently I do not have IP addresses on the bridges.
 
Last edited:
DHCP and IP addresses keep working as expected.
Yes, if you migrate a VM or CT on vmbr1 it will use vmbr1 on the target host as well.

On second thought, what do you mean with "I am going to put them on a seperate network"? As in different IP range, different DHCP assignment etc? then of course the above is not true and you'll probably not be able to (live) migrate without headache.
 
Last edited:
  • Like
Reactions: Johannes S
On second thought, what do you mean with "I am going to put them on a seperate network"? As in different IP range, different DHCP assignment etc? then of course the above is not true and you'll probably not be able to (live) migrate without headache

thanks. I will rethink that
 
Considered best practice that cluster traffic have it's own network/vlan.

I just create a additional vmbr (ie, vmbr1 or whatever number you want [best to use a VLAN number, if used]) and when I create the cluster, make sure it uses that network. I also change the Datacenter migration to use that network as well. To make sure that cluster network traffic never gets routed (and I know I won't be migrating between clusters), I use a 169.254.0.0/16 (subnetted, of course) IPv4 link-local network address, ie, 169.254.1.0/24 (I know, it's overkill, but so what).

No issues in production.
 
  • Like
Reactions: bellaireroad