Steps for changing network addresses of the cluster

[MartinF10]

Hi,

we have 4.1U3 Essentials Kit Plus with 1vCenter+3 ESXi hosts. We are planning to change IP addresses of these 4 hosts. What would you recommend as further steps.

My plan is:

1) Turn off Vmware HA

2) Migrate VMs from host1 to host2.

3) Remove host1 from cluster

4) change IP address of host1

5) add host1 to cluster

6) migrate VMs from host2 to host1

7) Remove host1 from cluster

😎 change IP address of host2

9) add host2 to cluster

6) migrate VMs from host3 to host1

7) Remove host3 from cluster

😎 change IP address of host3

9) add host3 to cluster

10) change ip address of vcenter

11) turn on Vmware HA

What do you think?

[marcelo_soares]

You don t need to migrate your VMs off the ESX servers at all. You can change the ESX IP address on the fly - just remove it from the vCenter, change IP and add it back again. I would do the following:

1. Disable HA;

2. Remove all 3 ESX from vCenter;

3. Change IP of all ESX servers;

4. Change IP of vCenter;

5. Add all ESX backwith new IPs;

6. Turn on HA.

This should work.

Cheers;

Marcelo Soares

twitter: @mtsoares42

[MartinF10]

Wrong. Unfortunately, it should not work. You cannot remove ESXi from cluster without putting it into maintenance mode - migrating vms are obligatory.

[marcelo_soares]

You can disconnect it and then remove. It should work.

[MartinF10]

Ok then sorry, this does work, but I am unable to re-add host in the cluster now - THe host cannot be admitted to the cluster's current Enhanced vMotion Compatibility mode. Powered-on or suspended virtualm machines on the host may be using CPU features hidden by that mode.

[marcelo_soares]

If you have EVC you will need eventually to power off all VMs when doing the new vCenter. Do you have different hardwares? Can't you disable EVC?

[MartinF10]

Yes I have different hardware. What I did is that I added it as standalone server in Datacenter object and drag&drop to cluster. Could that be a problem?

[marcelo_soares]

No problem. If the EVC cluster accepts the ESX, you are good. You may not be able to do that same thing on the vCEnter after changing the IP, but you can try.

[MartinF10]

After chaning IP of what? of vCenter?

[Josh26]

I realise it's late now but you didn't need to do all this. I've done this before:

Create routing between the old IP range and new, using a router
Add a second vmkernel to each host

Change DNS records appropriately. Assuming the hosts were added via FQDN, vCenter will just start using the new IP range

Change vCenter IP address

Remove old VMKernels.