I have the same questions, I have Vsphere 5.5 UPD 2 and VIO2.
I prepare windows image with vmware toos or cloud-init but without changes.
With linux guests i have no problems, but with windows guests when i launch a set of istances i receive the random error 'no valid host' and in in the vsphere console appears this messagge "error vmware tools are not installed".
Example:
- launch 20 linux instances results no problem
- launch 20 windows 2012 R2 instances results in 5/20 not working instances in a very random way,
Do you have an idea of how is the right way to prepare a windows image on VIO?
There is a bug in windows lauching? scheduling? of VIO?
I'm struggling with these problems, i have to prepare a working deployment :-(