How to seemlessly change the magagement IPs in the 3-node cluster?

[AndyBar]

Hello Proxmox community/Support,

I am in the middle of changing the management subnet, due to our network topology limitations.
I would need a detailed procedure/best practice document on how to seamlessly, without breaking the cluster change the management IPs of each NODE (3 NODES in the cluster):
root@pve0:~# pveversion --verbose
proxmox-ve: 5.2-2 (running kernel: 4.15.17-2-pve)
pve-manager: 5.2-1 (running version: 5.2-1/0fcd7879)
pve-kernel-4.15: 5.2-2
pve-kernel-4.13: 5.1-45
pve-kernel-4.15.17-2-pve: 4.15.17-10
pve-kernel-4.13.16-3-pve: 4.13.16-49
pve-kernel-4.13.16-2-pve: 4.13.16-48
pve-kernel-4.13.16-1-pve: 4.13.16-46
pve-kernel-4.13.13-6-pve: 4.13.13-42
pve-kernel-4.10.15-1-pve: 4.10.15-15
corosync: 2.4.2-pve5
criu: 2.11.1-1~bpo90
glusterfs-client: 3.8.8-1
ksm-control-daemon: 1.2-2
libjs-extjs: 6.0.1-2
libpve-access-control: 5.0-8
libpve-apiclient-perl: 2.0-4
libpve-common-perl: 5.0-32
libpve-guest-common-perl: 2.0-16
libpve-http-server-perl: 2.0-9
libpve-storage-perl: 5.0-23
libqb0: 1.0.1-1
lvm2: 2.02.168-pve6
lxc-pve: 3.0.0-3
lxcfs: 3.0.0-1
novnc-pve: 0.6-4
openvswitch-switch: 2.7.0-2
proxmox-widget-toolkit: 1.0-18
pve-cluster: 5.0-27
pve-container: 2.0-23
pve-docs: 5.2-4
pve-firewall: 3.0-9
pve-firmware: 2.0-4
pve-ha-manager: 2.0-5
pve-i18n: 1.0-5
pve-libspice-server1: 0.12.8-3
pve-qemu-kvm: 2.11.1-5
pve-xtermjs: 1.0-5
qemu-server: 5.0-26
smartmontools: 6.5+svn4324-1
spiceterm: 3.0-5
vncterm: 1.5-3
zfsutils-linux: 0.7.9-pve1~bpo9


Please advise,
Thank you.
Andy

 

[udo]

Hi,
you wrote nothing about your network config. Do you have an extra nic for cluster communication?
Do you have an bridge with vlans? So you can add one vlaan and use this as ring1 network for corosync. Than you can change your ring0 network...

Udo

 

[AndyBar]

Hi,
you wrote nothing about your network config. Do you have an extra nic for cluster communication?
Do you have an bridge with vlans? So you can add one vlaan and use this as ring1 network for corosync. Than you can change your ring0 network...

Udo

Thank you for the prompt response Udo.

Cluster network and management network are running on the same subnet. I am using ovs + bond nics. Switch ports are in trunk mode where the new VLAN is also specified. What happends with certificates (if any) or the ssh keys between the hosts if the IP gets changed ??

 

[udo]

Thank you for the prompt response Udo.

Cluster network and management network are running on the same subnet. I am using ovs + bond nics. Switch ports are in trunk mode where the new VLAN is also specified. What happends with certificates (if any) or the ssh keys between the hosts if the IP gets changed ??

Hi,
certificates and ssh-keys are not pinned to an ip-adress.

certificates represents an name and not an IP, but I hope you don't want to change the name too.

But if you have an subscription, your server id will changed (i asume) if you change you ip in /etc/hosts.

Udo

 

[AndyBar]

Is there a procedure about changing the management IPs ?

So far I can think of the following e.g.
1. Migrate all VMs off the host on which IP is to be changed
2. stop all proxmox services
3. Edit corosync.conf with new IP
4. Edit Interfaces config file - update new IP for the interface
5. Restart network services
6. start all proxmox services (including corosync obviously)
7. If everything is ok, migrate VMs back to this NODE
8. Repeat the steps from 1 to 7 for teh next NODE

Observation: My servers have extra nics so I have been thinking .... maybe it would be a good idea to implement a RRP? I guess that process is more tedious and more prone to the errors...

Please let me know what do you think ?

 

[AndyBar]

Hi,
certificates and ssh-keys are not pinned to an ip-adress.

certificates represents an name and not an IP, but I hope you don't want to change the name too.

But if you have an subscription, your server id will changed (i asume) if you change you ip in /etc/hosts.

Udo

I do not intend to change the dns names.


Is there a procedure about changing the management IPs ?

So far I can think of the following e.g.
1. Migrate all VMs off the host on which IP is to be changed
2. stop all proxmox services
3. Edit corosync.conf with new IP
4. Edit Interfaces config file - update new IP for the interface
5. Restart network services
6. start all proxmox services (including corosync obviously)
7. If everything is ok, migrate VMs back to this NODE
8. Repeat the steps from 1 to 7 for teh next NODE

Observation: My servers have extra nics so I have been thinking .... maybe it would be a good idea to implement a RRP? I guess that process is more tedious and more prone to the errors...

Please let me know what do you think ?