Multi boot Grub: which O/S responsible to update it on kernel upgrades ?

**Browser_ice** · October 12th, 2008

I have a multi-boot home PC (see signature). I am starting to wonder about something. The actual Grub used on boot time is the one created by the last O/S I installed.

But I am starting to wonder what will happen if my other Linux O/S have major upgrades causing them to try to update the grub. Will they update the grub on their partition (not used by boot) or will they try to update the real booting grub ?

In other words, I want my real booting grub to always reflect the last booting infos of all my O/S no matter the upgrade they did. Is that possible ?

**OutOfReach** · October 12th, 2008

I'm not too sure, but I think the OS (Linux OS) will update it's menu, which is not necessarily the main GRUB menu.

**Browser_ice** · October 12th, 2008

Originally Posted by OutOfReach

I'm not too sure, but I think the OS (Linux OS) will update it's menu, which is not necessarily the main GRUB menu.

Therefore, the real booting grub will be pointing to the old O/S's kernel. That's why I want to know how to have that real booting Grub with all updates of all O/S at all times.

**lswb** · October 12th, 2008

Take a look at this site, the author often posts on this forum also:

http://users.bigpond.net.au/hermanzone/p15.htm

Look for the section where he describes using a "grub partition"

A very small primary partition (I use 100MB, 50 is probably more than enough) is used to hold the grub bootloader that the MBR points. This is NOT a "boot partition", the kernels for each distro will reside on their own / filesystems. The menu.lst in this small partition will use chainloader statements to transfer boot to other bootable partitions. Those other partitions will have their own grub (or some other boot loader) installed. Each distro will update its own menu.lst without affecting the others. The website describes it very well.