Full Mesh Network for Ceph Server
Introduction
This wiki page describes how to configure in Proxmox VE (or any other Debian based LINUX distribution) a three node "Meshed Network" (instead of a network switch) as it can be used e.g. for connecting Ceph Servers or nodes in a Proxmox VE Cluster. This should also work with a 5-node cluster, general you need nodes_total - 1 = nic ports. The basic idea is running a small 3 node cluster with 10 Gbit network WITHOUT buying an expensive 10 Gbit network switch.
This should work with any kind of ethernet NICs, i.e. also 40 Gbit or even 100 Gbit ones. But for verifying this article, 10 Gbit Intel NICs were used.
There a two possible method to achieve a full mesh. General the fist one is the recommended one, because it is easier to set up and supports multicast.
Method 1
Create a "broadcast" bond with the given interfaces on every node. This can be done over the GUI or on the command-line.
GUI
On the GUI go to the node level -> System -> Network. Then click on "Create" and select "Linux Bond". In the Wizard make your configuration without gateway and set Mode to "broadcast".
reboot the node to activate the new network settings.
Command-Line
add the following lines to '/etc/network/interfaces'.
auto bond<No> iface bond<No> inet static address <IP> netmask <Netmask> slaves <Nic1> <Nic2> bond_miimon 100 bond_mode broadcast #Full Mesh
Then start the bond
ifup bond<No>
Method 2
Node1
/etc/network/interface
auto lo iface lo inet loopback iface eth2 inet manual auto eth3 iface eth3 inet static address 10.14.14.50 netmask 255.255.255.0 # Connected to Node2 (.51) auto eth0 iface eth0 inet static address 10.15.15.50 netmask 255.255.255.0 up route add -net 10.15.15.51 netmask 255.255.255.255 dev eth0 down route del -net 10.15.15.51 netmask 255.255.255.255 dev eth0 # Connected to Node3 (.52) auto eth1 iface eth1 inet static address 10.15.15.50 netmask 255.255.255.0 up route add -net 10.15.15.52 netmask 255.255.255.255 dev eth1 down route del -net 10.15.15.52 netmask 255.255.255.255 dev eth1 auto vmbr0 iface vmbr0 inet static address 192.168.2.50 netmask 255.255.240.0 gateway 192.168.2.1 bridge_ports eth2 bridge_stp off bridge_fd 0
route
root@pve-2-50:~# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.15.15.51 0.0.0.0 255.255.255.255 UH 0 0 0 eth0 10.15.15.52 0.0.0.0 255.255.255.255 UH 0 0 0 eth1 10.15.15.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.15.15.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 10.14.14.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3 192.168.0.0 0.0.0.0 255.255.240.0 U 0 0 0 vmbr0 0.0.0.0 192.168.2.1 0.0.0.0 UG 0 0 0 vmbr0
Node2
/etc/network/interface
auto lo iface lo inet loopback iface eth2 inet manual auto eth3 iface eth3 inet static address 10.14.14.51 netmask 255.255.255.0 # Connected to Node1 (.50) auto eth0 iface eth0 inet static address 10.15.15.51 netmask 255.255.255.0 up route add -net 10.15.15.50 netmask 255.255.255.255 dev eth0 down route del -net 10.15.15.50 netmask 255.255.255.255 dev eth0 # Connected to Node3 (.52) auto eth1 iface eth1 inet static address 10.15.15.51 netmask 255.255.255.0 up route add -net 10.15.15.52 netmask 255.255.255.255 dev eth1 down route del -net 10.15.15.52 netmask 255.255.255.255 dev eth1 auto vmbr0 iface vmbr0 inet static address 192.168.2.51 netmask 255.255.240.0 gateway 192.168.2.1 bridge_ports eth2 bridge_stp off bridge_fd 0
route
root@pve-2-51:/# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.15.15.50 0.0.0.0 255.255.255.255 UH 0 0 0 eth0 10.15.15.52 0.0.0.0 255.255.255.255 UH 0 0 0 eth1 10.15.15.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.15.15.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 10.14.14.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3 192.168.0.0 0.0.0.0 255.255.240.0 U 0 0 0 vmbr0 0.0.0.0 192.168.2.1 0.0.0.0 UG 0 0 0 vmbr0
Node3
/etc/network/interface
auto lo iface lo inet loopback iface eth2 inet manual auto eth3 iface eth3 inet static address 10.14.14.52 netmask 255.255.255.0 # Connected to Node2 (.51) auto eth0 iface eth0 inet static address 10.15.15.52 netmask 255.255.255.0 up route add -net 10.15.15.51 netmask 255.255.255.255 dev eth0 down route del -net 10.15.15.51 netmask 255.255.255.255 dev eth0 # Connected to Node1 (.50) auto eth1 iface eth1 inet static address 10.15.15.52 netmask 255.255.255.0 up route add -net 10.15.15.50 netmask 255.255.255.255 dev eth1 down route del -net 10.15.15.50 netmask 255.255.255.255 dev eth1 auto vmbr0 iface vmbr0 inet static address 192.168.2.52 netmask 255.255.240.0 gateway 192.168.2.1 bridge_ports eth2 bridge_stp off bridge_fd 0
route
root@pve-2-52:~# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.15.15.51 0.0.0.0 255.255.255.255 UH 0 0 0 eth0 10.15.15.50 0.0.0.0 255.255.255.255 UH 0 0 0 eth1 10.15.15.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.15.15.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 10.14.14.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3 192.168.0.0 0.0.0.0 255.255.240.0 U 0 0 0 vmbr0 0.0.0.0 192.168.2.1 0.0.0.0 UG 0 0 0 vmbr0