Multiple Proxmox clusters on the same subnet

[brucexx]

Just wanted to confirm , on 8.2 version we can have multiple PVE clusters on the same subnet as long as the "Cluster Name" is different , right ?

We are adding servers and creating new cluster , we will have 5 PVE cluster on the same subnet for about 2 week, after 2 week we will go down to 3 clusters which is the number we have now.

Thank you

 

[markusbernhard]

Will the VM:s be on the same subnet aswell? In that case you might want to set the mac address prefix to different values, otherwise you could find yourself having a spanning-tree shutdown on switch interfaces, if 2 vm:s get the same mac address.
Not very likely, but a real risk.
I don't see any other problems.

 

[brucexx]

MAC addresses are set manually, there is a DHCP reservation for all hosts. It is not possible to get the same MAC address.

Thank you

 

[alexskysilk]

MAC addresses are set manually, there is a DHCP reservation for all hosts.

This is a recipe for disaster on DHCP outage.

set your ips people.

 

[gfngfn256]

MAC addresses are set manually

Just be careful, if you replicate/restore etc. an LXC/VM from one cluster to the other.

 

[brucexx]

This is a recipe for disaster on DHCP outage.

set your ips people.

I am confident in the DHCP setup , the bigger you scale the more flexibility is needed especially when it comes to backup and secondary site availability. DHCP servers are on a VM with redundancy and the other one on a redundant piece of hardware. Hosts are setup with no expiration so only if they reboot they will request an ip address from DHCP. The PBSs + DHCP setup + small TTL for DNS give us more flexibility to failover on a VM to VM basis to another site (vs. BGP which will do whole /24). White testing we can fail over in a matter of 2-3 min per VM to a datacenter 2.5k miles away, we can also failover whole clusters that way.

 

[brucexx]

Just be careful, if you replicate/restore etc. an LXC/VM from one cluster to the other.

I moved VMs from one cluster to the other with that setup before , no issues. As long as you don't have them running at the same time on two cluster it is fine.

Thank you