Hi Gerhardo,

Here you go:

1. Can I use 16 slot lic if I want to use only 16 of 24 available slots? Yes- that is possible.

2. We have networker version 7.3 - do I need an upgrade to 7.6? Yes- 7.3 and 7.4 are EOL/EOSL.  I'd go 7.6 SP2

3. I have daily inc and weekly full backups. If I install on each virtual machine a networker agent - how is backup data transfered? Is it going via virtual network or is there a faster possibility? Yes- It will go through the virtual network.  A faster way would be to use VADP with 7.6 SP2.

4. The attached jpg has only one virtual backup server. Is it possible to have a second (as for other servers) synchronized virtual backup server for high availability? Not really.  But there is a documented disaster recovery solution with a separate NetWorker Server and replication of the NetWorker data.  Located here.

I hope this helps..

Allan