Continue from "Can anyone help me"
After a lot of experiments and more than 10 installations i manage to install Sabayon 7 on a usb hdd connected on a VAIO VGN SZ 650.
First of all the partitioning: anaconda, on use all space option, propose the configuration of the target hdd with lvm (large volume manager), but after 2-3 steps on grub, is not configuring th kernel line as well to support lvm on boot. That's why i had the errors during boot procedure. So the last time i use the custom partitioning to create normal partitions without using lvm. (i create sdb1(boot), sdb2(root), sdb3(home), sdb4 and sdb5 (swap)). But even and with this configuration during boot procedure the system asked for root partition. The answer is "/dev/sdb2".
Second issue the login screen: it was written my name (full user name), but i could'n login the system. I pass this problem after i wrote again my user name. (During installation procedure anaconda ask for root password, user name, full user name and user's password with this sequence).
Third issue was the big amount of updates (328) from the latest release. That's very good because the user has a new system every day but there are a lot of problems inside these updates.
I believe that Sabayon is a magnificent distribution of linux. But anaconda must be more helpfull with new users especially on background procedures such as creation of grub and partitioning.
Thanks for read this post. I hope and waiting for a newer version without these problems,