false assumption when installing Grub to MBR?

[Russell Gadd]

(please bear with me as I am a Linux newbie)
(sorry this seems to be filed as affecting Gnome system tools - i wasn't aware that the bug tracking system had allocated this as such - it's an installation issue)

I need to install Ubuntu multibooted with several versions of Windows and the first time I did this it overwrote the MBR with grub without asking me if I wanted it in the MBR or in the root partition. This screwed up my system.

I successfully installed Debian stable which did ask this question, so eventually I tried Ubuntu again this time using "expert" mode. After some finger crossing it did ask me where to install grub, so I am now ok.

I think the problem might lie in the default non-expert installation, which probably looks at the partitions in the MBR and if it doesn't find any bootable items assumes it can go ahead without troubling the user. Mostly a fair assumption - but not always - as follows. However if this is not the case maybe all you need to do is to warn the user to use "expert" mode when there is another OS around.

I use a boot manager called BootitNG which allows many (more than 4) primary partitions on the drive. It resides in the MBR and before passing control to the OS to be booted it loads the MBR partition table with up to 4 primary partitions. When the OS gets control it can only see these 4 partitions and thinks the rest of the drive is unallocated / free space (so far no OS I have used has tried to use this space). So there may be other OS's on the drive even though the OS booted (Ubuntu) can't see any bootable partitions. The crux is that it shouldn't assume it can simply install itself in the MBR. Maybe you need another option in the install menu?

[Colin Watson (cjwatson)]

Thanks for your report. This is also bug 47135.