Advice on proxmox install and config

[Cezar]

Hello!
I have to replace an old server. The new server will have proxmox and a vm running a licensed cpanel/whm. In order to replace the server, I have to go to the datacenter and make the switch.
I was hoping I can install the server off-location and just drop it in place.
I see that proxmox users advice on making a fresh install if the IP changes.
I have two question:
1) Can you please tell me if there's a procedure to install the server and then change the ip before taking it to the datacenter, without causing system errors?
What would you advice me in this case?
2) Can you please give me some indications on how to route all traffic to the VM, except the ports needed for the proxmox services? I have 2 public IPs at the datacenter and I want to divert all trafic to this cpanel VM.

Thank you!

 

[LnxBil]

1) Can you please tell me if there's a procedure to install the server and then change the ip before taking it to the datacenter, without causing system errors?
What would you advice me in this case?

We do this all the time. We created a "network simulator", a special VM with two network interfaces one facing our lan and the other in a special vlan and then untagged on a switch in which we plug the servers. On the VM, we simulate the target networking including DNS, DHCP, gateways etc. in order to test out everything and then deliver to the customer. The plug it it, start and directly enjoy their new servers.

2) Can you please give me some indications on how to route all traffic to the VM, except the ports needed for the proxmox services? I have 2 public IPs at the datacenter and I want to divert all trafic to this cpanel VM.

Why all traffic? You normally need only to forward what you need and that is at most 10 ports, that is already a very high number considering there are 128k ports alone with tcp and udp not including all other possible protocols.

 

[Cezar]

Thank you for the reply.
Your VM solutions sounds like science-fiction to me I have no clue on how to do that. So you're saying you are leaving proxmox as is, but when you deliver the server to the datacenter, shouldn't the proxmox ip change ?
About the ports, I agree, only the cpanel needed ports will have to be forwarded.

 

[LnxBil]

Your VM solutions sounds like science-fiction to me I have no clue on how to do that. So you're saying you are leaving proxmox as is, but when you deliver the server to the datacenter, shouldn't the proxmox ip change ?

I configure everything on premise including the target IP, I just simulate the whole target network (basically only the gateway is strictly necessary for that, but every other involved service is a nice to have: NTP, DNS, proxy, package mirrors, ...) and then everything is already as it should be.

We also setup whole cluster appliances with SAN this way, e.g. an complete Oracle RAC. The customers only have to connect everything as described in the cable connection plan, startup and enjoy.

 

[Cezar]

Is there any links you could provide so I would have some resources to analyze and solve my problems?
1 - how do i change the ip of proxmox without reinstalling, without causing errors in the system
2 - how do i make the routing to the vm ?
Thank you!

 

[LnxBil]

General advice: If you're not familiar with Linux (especially Debian-based systems), do not perform advanced operations and ALWAYS test things first on another machine (e.g. virtual machine running PVE).

1 - how do i change the ip of proxmox without reinstalling, without causing errors in the system

Why should there be errors? Just the plain Debian style by changing the IP in /etc/network/interfaces and /etc/hosts. The problematic task would be to change the hostname, because it is stored everywhere.

For a single server, you can just choose a plain hostname like pve. It does not matter what you choose for a local name on you machine and it has not to match the official DNS name for simple operation.

2 - how do i make the routing to the vm ?

This is no special PVE problem, just plain old networking, which can be done with any OS capable of running an IP stack. I'd recommend to read up on routing on Linux in general. Depending on your knowledge, this can be a steep learning curve.

Easiest setup is to use an IP alias on your machine in the same subnet as your target machine and connect then.

 

[Cezar]

I will try taking your advice. Thank you!