I installed Knoppix 3.4,SuSe 9.1 and Fedora Core 2(don't ask me why,please!) onto 3 different partitions then i created a fourth partition for the home directory:how can i share home directory,username, KDE settings and anything else usefull between the 3 distro?Should i create a user with the same name and home path for all the distro?

To share users, settings, etc, you'll want to set up /etc/fstab so that /dev/hda4 is mounted to /home. The UNIX filesystem is beautiful because all of your personal files, and the files of all other users, are stored in /home, so it can be easily shared.

There is a good page called "How to edit and understand /etc/fstab" on tuxfiles that can show you how to do this.

Simply, it should be similiar to:

I'm not sure about this but some of those distros you mentioned might have graphical tools to manage fstab. But if in doubt do it manually!

I hope this was helpful.

I have 2 linux from scratch builds sharing the same "home" partition......
BUT each LFS build has different user names, otherwise DCOP will lock up
hard!!

<edit/> and each LFS build has different /root partitions.........don't try to
use the same /root between 2 or 3 different installs.........that will
"fubar" everything.........

For two days all went okat but now when i start Fedora ang log in as user the session last less then ten second and the error says that i don't have permission to write to home direcotry.Why???