I never bothered about this question because I have always created sufficient space on my disks by primary partitions mostly. But then, the question just came to mind: can’t openSUSE be also booted off an extended partition (logical volume)?
If so, how? Where does the option lie in the installation procedure?
I think that there is an option in the ‘booting’ section of the installation where I think I have seen to set a option to boot from the extended partition ( I think it should make me set the boot partition to the correct extended partition in the list).
Am I right? If not, then, what can be done to get extended partition be the root mount point for the openSUSE?
Sure, Linux can be installed in a logical partition. You can’t use the extended partition, that’s just a container for logical partitions and doesn’t have any blocks of its own, but you can use the logical partitions as if they were real partitions. The caveat is that GRUB must be able to read that far into the disk for booting purposes, older BIOSes have limits on the cylinder number it can read. But that’s no different from a real partition. That’s why it’s recommended to put /boot on the low cylinders whenever possible.
The installer automatically copes by installing boot code in the Master Boot Record that points to the file /boot/grub/menu.lst on the Suse root partition. That file is set up to also contain a pointer or pointers to previously installed operating systems (e.g. Ubuntu, windows, whatever).
Hi ken_yap. I believe the extended partition has a Boot Record. Look in Yast’s Bootloader GUI under the Tab “Boot Loader Installation” –> Boot loader location –> boot from extended partition.
I think that option puts Grub code in the Boot Rec of the extended partition, thus providing a pointer back to /boot/grub/menu.lst on the root partition.
Which is a handy way to get over the high cylinders problem in some cases (cases where the start of the extended partition isn’t itself too far away).
IIRC, IMHO and several other disclaimers including E&OE
You’re probably right about that. But you could just as easily use the boot record of the first logical partition contained in it, which would be just a cylinder or two away.
I don’t know much about partition boot records because I don’t have situations needing chaining, but also because I prefer to do it all from the MBR if possible.
Yes you can install / on a logical partition, no problems there.
Yes you can boot off it. The questions are where do you put the GRUB boot sector, how do you give control to it, and what menu.lst does it use. There are lots of permutations for that. I believe swerdna has done quite a bit of research in that area. But the questions would be the same if you were dealing with a physical partition.
