thanks for your advices CrashedA,

>I would put lilo on the MBR from the first O/S installed,
***one expert has told me to also load the first distro into the LAST partition,
so as to force grub to register all subsequent distros.
what dyou think of that ?

>all the others would put their lilo (or grub if preferred) on the partition.
***ok, nobody seems to be arguing about that.

>These systems would then be added into the main lilo as 'other' operating system
>which will boot into the bootloader on the partition.
***and on bootup, will grub offer a choose_your_distro menu ?

***i just read in the YAST manual about putting a 10M partition at the
beginning for the boot loader and the kernel. is that necessary ?

So at the moment, summary advices seem to indicate
(1) boot /kernel partition 10M
(2) swapfile 1G
(3) several logical (say 10G each) in an extended
(4) one primary 10G for the first distro
(5) the rest for data

how does that sound ?