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#26 2012-06-27 08:04:11

ninian
Member
From: United Kingdom
Registered: 2008-02-24
Posts: 726
Website

Re: Some thoughts about grub2 and bootloaders in general.

olive wrote:

You cannot boot directly a kernel under another partition with syslinux, you have to chainload the other partition: https://wiki.archlinux.org/index.php/Sy … ainloading. See also the documentation of chain.c32 http://www.syslinux.org/wiki/index.php/ … /chain.c32. Syslinux install only on a partition, if you have several Linuxes, each of them should have syslinux (or another boot loader) in its partition. So in you case I would decide to have a /master/ syslinux installation on a linux distribution on the drive booted by the Bios, that have a menu that 1) load that distribution and 2)  Give the possibility to chainload the other distributions. Now you must have an mbr for the drive that is able to chainload an OS from a logical partition. I think the altmbr.bin of syslinux can do that from a given logical partition (be sure to read http://www.syslinux.org/wiki/index.php/Mbr to understand how to use it)

Many thanks for the reply and detail of your explanation. Will digest and experiment further!

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#27 2012-06-27 09:39:36

Mr. Alex
Member
Registered: 2010-08-26
Posts: 623

Re: Some thoughts about grub2 and bootloaders in general.

PReP wrote:

An edit to that, adding dbus and consolekit...

Oh yeah, the program official documentation STILL doesn't know the purpose for. big_smile

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#28 2012-06-27 14:21:45

the.ridikulus.rat
Member
From: Indiana, USA
Registered: 2011-10-04
Posts: 765

Re: Some thoughts about grub2 and bootloaders in general.

bwat47 wrote:

I ended up just switching to grub2 anyway. The wiki page makes it look horribly complicated at first glance, but its really not that bad.

The wiki page is long because it explains all the possible ways of installing grub(2), it does not mean grub(2) is complex to setup. Many users just see the size of the wiki article and think that grub(2) is complex without even reading the contents. See my reply to a post in arch-general http://mailman.archlinux.org/pipermail/ … 27670.html about grub-legacy to grub(2) change which also answers some of the questions asked here.

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#29 2012-06-27 20:04:51

vacant
Member
From: downstairs
Registered: 2004-11-05
Posts: 816

Re: Some thoughts about grub2 and bootloaders in general.

olive wrote:

You cannot boot directly a kernel under another partition with syslinux, you have to chainload the other partition

I used to have Arch and Kubuntu dual-boot. I found they coexisted quite nicely on a shared /boot partition (different kernel & initrd names). Once the kernel has loaded, whatever is specified in "root=" is of no concern to the boot loader. I quite like the KISS attitude of syslinux.

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#30 2012-06-28 11:39:10

Mektub
Member
From: Lisbon /Portugal
Registered: 2008-01-02
Posts: 647

Re: Some thoughts about grub2 and bootloaders in general.

Even tough I agree with most opinions here, I still find this Grub2 an overkill and at times quite unreliable.

On my laptop I have six Linux distributions, and none of them is able to build a working grub.cfg, even after having reinitialized several partitions that I was going to reinstall anyway.

I always get:

grub-mkconfig -o /boot/grub/grub.cfg
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.2.0-25-generic
Found initrd image: /boot/initrd.img-3.2.0-25-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Ubuntu 12.04 LTS (12.04) on /dev/sda10
Found Slackware Linux (Slackware 13.37.0) on /dev/sda13
Found Arch Linux (rolling) on /dev/sda7
error: out of memory.
error: syntax error.
error: Incorrect command.
error: syntax error.
error: line no: 259
Syntax errors are detected in generated GRUB config file.
Ensure that there are no errors in /etc/default/grub
and /etc/grub.d/* files or please file a bug report with
/boot/grub/grub.cfg.new file attached

I am not asking for help, I have enough knowledge to find a solution by myself.

But must people really dig into such matters ? Edit a convoluted configuration file ?

I should be running a Linux distribution and doing my job, not fiddling with Grub.

Just my 2 cents,

Mektub


Follow me on twitter: https://twitter.com/johnbina

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#31 2012-06-28 18:11:26

ZekeSulastin
Member
Registered: 2010-09-20
Posts: 266

Re: Some thoughts about grub2 and bootloaders in general.

Mektub wrote:

But must people really dig into such matters ? Edit a convoluted configuration file ?

People sure as heck seem to love doing it for other bootloaders if this thread is any indication; forget about grub-mkconfig and just write a simple config by hand if it's giving you issues, as it's really not much more complex in that case than any other bootloader.  (Also file bug report etc.)

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#32 2012-06-28 23:40:47

ninian
Member
From: United Kingdom
Registered: 2008-02-24
Posts: 726
Website

Re: Some thoughts about grub2 and bootloaders in general.

Well, I've been testing out Syslinux on my setup and I've successfully managed to physically swap drives so that I now boot various Linux distros from my first drive and boot Windows XP from the second partition on the second drive. Very straightforward and logical, just need to keep focussed on where the chain loading is going.

Must admit to feeling well in control and not missing Grub (1) much at all. So for me, I'll pass on Grub2 and resist its "enhancements" for now.
KISS rules at the end of the day!
wink

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#33 2012-06-29 00:06:59

Gusar
Member
Registered: 2009-08-25
Posts: 3,605

Re: Some thoughts about grub2 and bootloaders in general.

I've been syslinux all the way for some time now. Except on my crazy netbook. Among it's many quirks is not liking syslinux, so I've had grub-legacy on it. Until today. After a bit of hesitation, today I installed lilo on it. And what do you know, it boots smile. And is very simple to configure. So now I'm grub free.

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#34 2012-06-29 21:56:02

chungy
Member
Registered: 2009-09-07
Posts: 32

Re: Some thoughts about grub2 and bootloaders in general.

This thread's a little bit of a doozy. Some things:

* GRUB2 is not really as complicated as what people seem think. From my viewpoint, it appears the fact that GRUB does have a ton of modules to support almost every filesystem in the world, LUKS, RAID, LVM, MBR, GPT, BSD labels, etc is throwing people off and making it seem complex. GRUB's core is actually still fairly small and simple; its ability to load modules for extra functionality is a good thing and necessary for its goal of booting every OS under the sun. It'd be a lot like calling the NES complicated because it has a ton of accessories. wink

* GRUB2 doesn't discourage or forbid the practice of writing config files by hand, nor have they changed the format in drastic ways to make it more complicated than necessary. The simple matter is that the format is different because GRUB has evolved; I've seen elsewhere people that complain about curly braces and more bash-like syntax, but that's really no big deal.  If you've ever copy+pasted blocks of a GRUB Legacy config file and make your boot loader unusable because the indentation or something silly like that was wrong, you should be quite thankful for the more flexible new format smile
Also, the GRUB developers are fairly rightfully proud of their auto-generation of grub.cfg via grub-mkconfig.  It makes the bootloader accessible to many more people (or especially distro installers, who can outsource all the detection/conf-generation code to GRUB themselves) who want to just install a bootloader once with minimal fuss.  grub-mkconfig tries to detect all the OSes installed on the system and generate menu entries for them with reasonable defaults; and maybe it's just me, but with past experience of multi-booting different OSes, it's fairly jaw-dropping that GRUB makes it seem like no issue at all to just generate up some lines and have Windows and Mac OS X booting directly from it.

Read the documentation ("info grub" or the web site) for more information on the config format.  It is different from GRUB Legacy, but not worse.

* LILO and SYSLINUX are not necessarily any simpler than GRUB! To make this clear, I am not going to make any absolute defences of GRUB or LILO/SYSLINUX is simpler, because it VERY MUCH depends on each person's own computer.  if you are trying to boot multiple Linux distributions or even Windows sometimes, they can become quite a pain... but they are very easy and simple for a single-OS scenario (I myself use syslinux all the time to make bootable USB drives, but I can't imagine it being difficult with grub either), but IMO they get quite hairy and cumbersome when you grow beyond that.

Well, in short, bootloaders are a very important part of your system, but don't get quite so emotional over them! If you use SYSLINUX and it works great for you, well that's fine and fantastic.  If GRUB2 suits your needs (which it especially should in multi-boot situations or RAID/LVM situations), that's fine too.  Once you have a bootloader that works, you shouldn't think about it so much afterwords tongue

GRUB2 has a lot of functionality and I personally would recommend reading its manual (again, "info grub" or web site) if you want to know more about it, but for the large part, the manual isn't a necessary read to just get it running.  (also... I come from the days when multi-booting was near-impossible and bootloaders were too esoteric to configure even if you memorized their documentation, so maybe it gives me a lighter view on GRUB... but damn, I can't help but to be impressed that it JUST WORKS in my own LVM+btrfs set up without any independent /boot partition)

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