Its easy:
Make a Zeroshell CD with addon Zeroshell.img (UltraISO or ISO IMAGE)
1. Boot from Zeroshell CD
2. go to shell
3. create the filesystem on Harddisk.
5. extrakt Zeroshell.img to Harddisk
Reboot from Harddisk
Enjoy
http://alaksha.blogspot.de/2012/09/how-to-install-zeroshell-to-hard-disk.html
It works, i have test it with Citrix Xenserver, ESXI, Proxmox ….
Best regards
Dirk