Question about removing a HOST and re-adding it with other management IP

[EduardoBP]

Thanks in advance for your help.

I have an environment with two datacenters/clusters inside my virtual center 2.5

One of the clusters consistes on two 3.5 ESXi licensed nodes. Each one of them has 2 VMKernel ports form management. One of them has a IP ( A.A.A.1) with no VLAN, the other port is in VLAN111 and has IP (B.B.B.1). The other ESXi host has A.A.A.2 and B.B.B.2 IP's.

The other cluster has two 3.5 ESX (not i) and they have only one managemente port/IP (in the VLAN111, the same as the other cluster)

The first cluster appears associated to virtual center with the NO-VLAN port (IP A.A.A.1 and 2). This is a problem for me because i need to gain access to the first cluster from other machines that has no visibility over the A.A.A.x subnet, but it has visibility to the VLAN111. If i connect to the virtual center, it shows me the A.A.A.x IP's but when i try to access to them, I'm unable.

I'd like to do the following WITHOUT affecting the first cluster :

-Remove each host from my virtual center (¿the VM's will continue working with no problem?)

-Re-Add each host from the virtual center, but this time I'll add the VLAN111 IP's (B.B.B.x)

My question is if these is going to generate problems-instabilities on my platform.

Thanks in advance

[schepp]

Hey,

just tested it with ESX 4 and vCenter 4.

Removing a Host from a Cluster requires the maintenance mode. But removing the host completly from vCenter works without any impacts on the virtual maschines running on it.

Re-adding the host to vCenter works without a problem.

Greets

[EduardoBP]

Both ESXi hosts are inside a cluster (with DRS but not HA). I don't want to break the cluster, I only want to re-add hosts on another IP.

I'm going to do "right-click" over one host, and selecting "remove", then repeating with the other host.

At this moment all services into the HOSTs are going to keep working OK ¿no?

After the removal (without maintenance mode), I'm going to add the hosts but using the other IP, the accesible one. I'll regain the same kind of access after this

¿Am I correct?

Thanks in advance

Understand that I'm going to do this in a production environment, and I don't want to crash more than a hundred users... That's the reason of this detailed question.

[schepp]

Yes, when you remove the hosts from the vCenter, the virtual maschines on that hosts will continue running without any interference.

By the way, in your first post you mentioned that the hosts have 2 VMKernels. Maybe you just used a wrong term, but a ESX/i ist connected to the vCenter by it's Service Console and it's vswif, not the VMkernel.

[EduardoBP]

I'm attaching an image of the real config of one of the ESXi hosts. I've marked in red the two vmkernel ports. No vswif beacuse vswif it's only available for ESX hosts, not ESXi.

I'm hoping not to destroy everything in my company... THANKS

[mark_chuman · Accepted solution]

This process worked for us when moving ESX servers from old VC(2.5) to new VC(4.0).

1. Unconfigure HA and DRS on farm.

2. Disconnect all ESX servers in farm.

3. Remove all ESX servers in farm.

4. Add ESX server to new cluster in VC (4.0).

5. Configure HA and DRS on new farm.

Used for over 700 ESX servers with zero impact.

[EduardoBP]

Thanks everybody.

Finally I "threw into the pool" and did it exactly as mark.chuman says and all seems OK, at least no one has complained...