vCloud Director 5.1 prepare hosts with busy load

[aha_tom]

Hi, we have 3 hosts in a vSphere 4 cluster with vCenter 5.1. I am planing to install the vCloud agent on all three hosts.

My problem is there are currently tons of VMs running on those 3 hosts. If I follow the Provider VDC Setup Wizard and just add the root credential for those 3 hosts, will it cause any outage to the VMs running on those hosts? Will it force those hosts to go into Maintenance Mode and cause outage? Or vCloud will simply report failure because there are VMs running on those hosts?

If vCloud will just report failures, I suppose I will then have the option to prepare each host individually, which allows me to shift some work load to the rest 2 hosts?

[cfor]

To start - you can do one host at a time by putting it in maintenance mode first - then preparing it - then remove it from maint mode.  Doing this should have no impact as the running systems in the cluster as they should be moved off to the other systems while the host is in maintenance mode.

That all said... cloud is really designed to be the only function running on a cluster - it CAN work in a shared setup but this is not the preferred way of running it.  The standard setup would be to have a cluster without anything else that cloud can fully control.  (If this is not possible you can create a resource pool on the cluster and let cloud control that)

[aha_tom]

thanks for the reply. I can't seem to find an option for me to prepare each host one by one, apart from adding them all in one go option in the Provider VDC Setup Wizard. Can anyone show me where I can do this? If I go to Hosts in vCloud Director, there is no "Add a Host" option.

[IamTHEvilONE]

You don't add a host, you add a cluster of hosts.  We basically detect all hosts in a cluster, and all should be prepared to allow load balancing across all hosts.

When you add a Provider and need to prepare the cluster, vCloud will probably try to prepare all the hosts at the same time.  This is normal. 

However, you can cancel the Maintenance Mode request from vCenter to stop the process on all but 1-2 hosts in the cluster.  Once they are prepared, you can then prepare a subset of hosts from the appropriate screen in vCloud Director.

[aha_tom · Accepted solution]

Here is what I have done: I followed the Provider VDC setup wizard and when reach the host preparation step I put in wrong password for the hosts. The host preparation failed of course. I then have the options to prepare each individual host. I think I just been over cautious here. The host preparation step should stop if there are live VMs on the host.

[JayhawkEric]

FYI...  The host prep process will put the host in maintenance mode before installing the agent.  If there's any VM's on the host they will be migrated to other hosts in the cluster.  If they cannot be moved then host prep on that host will fail.