Thanks for the input.
Unfortunately the mentioned article is from 2011 and with vSphere 6 things in FT have change.
Especially regarding limitations and as far as I have understood the secondary VM is now using it's own VMDKs.
Does anyone know if a FT-protected VM has to be VMDK-only? Or can it still use OS-mounted storage like NFS/iSCSI within the VM?
Regards