Re: Managing multi grub installs

[Andrey Borzenkov]

В Mon, 10 Mar 2014 08:40:53 +0530
Rustom Mody <address@hidden> пишет:

> Hi
> 
> My earlier thread
> http://lists.gnu.org/archive/html/help-grub/2011-01/msg00017.html
> 
> Thanks to help from Jordan Ugla there, in particular, the suggestion
> to use 'configfile',  things have been mostly working for the last 2-3
> years. Recently it stopped working so this mail. More details below.
> 
> My blkid excerpts
> 
> /dev/sda2: LABEL="Boot500G" UUID="..." TYPE="ext2"
> /dev/sda5: LABEL="Debian500G" UUID="..." TYPE="ext4"
> /dev/sda6: LABEL="Ubuntu500G" UUID="...." TYPE="ext4"
> /dev/sda7: LABEL="DebOld" UUID="..." TYPE="ext4"
> 
> In short I have multiple linuxes with their own /boots in sda5,6,7
> And a /boot standalone in sda2.
> The mbr points to sda2.
> sda2 is not mounted in any OS so it does not get meddled with on upgrades
> 
> It contains entries written by hand like
> menuentry "Debian  configfile chaining" {
>         search --set --label Debian500G
>         configfile /boot/grub/grub.cfg
> }
> 
> And this was working for about a year.
> 
> IOW: the respective OSes would only upgrade their own boots under
> their respective filesystems.  They would not stomp on each others'
> toes and my handwritten boot would configfile-chain to them.
> 

Why do not simply chainload each bootloader? I.e.

menuentry "Debian bootloader" {
  search --set --label Debian500G
  multiboot /boot/grub/i386-pc/core.img
}

(adjust platform and paths as needed). Or simply configure each OS to
install bootblock in respective partition and use

chainloader +1

The problem with configfile approach is, it is not clean environment.
You still get at least $prefix which refers to original grub2. Using
bootloader chaining will give you clean bootloader instance for each OS.

> Then (small nuisance!) after upgrading the debian started introducing a
> load_video function that would error out when chained with configfile.
> 
> No issue: I'd just delete that line after an upgrade and things kept
> running smoothly.
> 
> But after my most recent debian-testing upgrade it just stopped working:
> the second configfile just does not reach and the machine keeps rebooting.
> 
> As a current hack Ive made a new entry that works
> menuentry "Debian 500 handedited" {
>         linux (hd0,5)/boot/vmlinuz-3.12-1-686-pae root=LABEL=Debian500G ro
>         initrd (hd0,5)/boot/initrd.img-3.12-1-686-pae
> }
> 
> How do I keep configfile working??
> 
> Thanks
> Rusi
> 
>