Zero downtime for vApp in vCloud Director

Hi Guys,

Just want to your advice, is it possible to achieve Zero downtime for vApp within site.

As I see we can have vSphere HA which will bring VMs up on within 5 minutes.

But I have customer who needs facility to do rolling upgrade and have no downtime even during maintenance window.

can you help me from your experience?

For such solution i have always offered FT (for one vCPU) or in-guest clustering i.e. Linux/MSCS/Veritas/RAC offering.

But none of these are supported by vCloud director.

Then how do we offer such solution.

Appreciate a response on this.

Hope this is the right forum

Thanks,

Preetam