[blfs-support] Anybody installing os-prober for grub?

Paul Rogers paulgrogers at fastmail.fm
Tue Jul 28 13:46:04 PDT 2015

> yes, I used to use it.  I don't think that I actually _needed_ it,
> set +e # something caused it to bail somewhere
> # install -v -Dm755 linux-boot-prober /usr/bin/linux-boot-prober
> # install -v -Dm755 os-> prober /usr/bin/os-prober

This is from an install script.  Got one of those from installing 1.56,
but it also includes doing 10 different patch files!  I already checked,
1.62 won't take them all, suggesting there should be a new set of
patches.  I haven't "gotten into" them and tried to see which are in the
code and which might be adaptations to something resembling LSB.  I was
hoping sombody'd found some.

> I have never found os-prober to work properly.  At least when I
> install non-lfs systems, the grub.cfg is so totally screwed up that it
> is unusable.

I think you're complaining, in part, about grub-mkconfig there.  It
tries to throw every option it can at each stanza.  It _is_ a mess!  I
get those without having os-prober installed.  Like both of you, I
severely edit the file.

> As an exercise I installed Fedora 22, Fedora Server, Debian,
> Slackware, and Ubuntu on a system.  When I checked the boot.cfg there
> were, IIRC, 47 entries.  Every kernel was set up to install on every
> partition, sometimes multiple times.  Fedora wants to use /boot/grub2/

grub-mkconfig adds a "single" stanza for every kernel by default.  That
can be controlled in /etc/default/grub, to some extent.

> and the others want to use /boot/grub/.  Of course all but Slackware
> had an initrd file.  To give an example, a 3.14 kernel might be set up
> to boot on /dev/sda4 that has no 3.14 modules.

That, and the kernel boot parameters, what I want it for.

> What I found was that I needed to manually edit the grub.cfg file
> after every install after the first.  With the last install, the
> grub.cfg file was somewhere around 500 lines.  I removed all the cruft
> and set up the grub.cfg file properly and it was only about 35 lines.

Yeah, I never let grub-mkconfig touch my file!  I'll use my smplified
file and cut/paste with a couple xterms.

> My point is that if you don't know what OS is on each partition, then
> you shouldn't be doing LFS.  os-prober serves no useful purpose.

Yes, it does.  I've got CentOS-6.6-x86-64 running on my i7 box, and if I
wordwrap the "linux" command in its grub stanza, it's 3 lines long!!  No
way I'd figure that out.  And no, Anaconda won't set it up so's one can
chain-load it.
Paul Rogers
paulgrogers at fastmail.fm
Rogers' Second Law: "Everything you do communicates."
(I do not personally endorse any additions after this line. TANSTAAFL :-)


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