On 22/04/15 19:20, Andrei Borzenkov wrote:

On Wed, Apr 22, 2015 at 10:16 AM, Basil Chupin <blchupin@iinet.net.au> wrote:

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On 21/04/15 00:21, Keith Roberts wrote:

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Hi all.

Following on from my post about GRUB hanging, I just wondered what - if any - disaster recovery options you use to fix a broken GRUB boot loader?

I�m in the process of adding a failsafe GRUB boot process to my DR list of options.

I have mentioned this article in the past several times:

http://www.linuxidentity.com/us/down/articles/LSK_multi_distro_install_US.pd...

which contains all the essential info.

The only thing to watch for is that it is written with Ubuntu in mind and therefore some of the instructions given are for legacy grub and not for grub2 - and so one must do some mental adjustments to make the commands work for grib2, but this is painless really......

The only place where grub legacy is mentioned is "Recently, GRUB 2 has replaced older versions of GRUB which are now called GRUB legacy.". May be I'm reading the wrong article.

No, you are correct when you read the above. But when you read further you will find that (as I already mentioned) the installation of the boot loader is for Ubuntu where Ubuntu does not use the term "grub2" but continues to use the legacy description of Grub. For example, a major command to put Grub2 onto a non-Ubuntu running distro such as openSUSE is written in the article as- grub-install –root-directory=/media/btldr /dev/sda p16, Installation of boot loader on partition, paragraph 2. I therefore mentioned that the instructions were indicating grub legacy instructions because of their lack of mention of grub2 and which therefore had to be changed to make them work with grub2 - for example, the above command should read '*grub2*-install --root-directory..........'. And, BTW, the article *also* contains a typo in this command: the command should read- grub2-install *--*root-directory-media/btldr /dev/sda

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The best advice that I can give for the recovery of a broken grub2 bootloader is to MAKE A BACKUP OF IT!

How do you make backup of grub2? I'm really curious.

By thinking outside the square one works out that the OP is talking about the contents of the /boot directory and therefore the suggestion to make a backup of the bootloader - which happens to be in the /boot directory Or if you are using a bootloader to boot multiple operating systems, then do a backup of /mnt/btldr/boot which is mentioned in the article.

But if you want to create a new bootloader after, say, a new kernel is installed you need to run, AS ROOT, IN A TERMINAL:

grub2-mkconfig -o /boot/grub2/grub.cfg

What do you mean when you say "create new bootloader"?

Exactly that. You may have another fancy word for it but I call it the bootloader which is what the Grub Menu uses to boot your system - or any other system which you have installed (see the article I mention above). The term "boot loader" is also used in YaST - except that it is spelt as 2 separate and distinct words unlike myself which combined them into "bootloader". If this has confused you then I am very sorry. BC -- Using openSUSE 13.2, KDE 4.14.6 & kernel 4.0.1-1 on a system with- AMD FX 8-core 3.6/4.2GHz processor 16GB PC14900/1866MHz Quad Channel RAM Gigabyte AMD3+ m/board; Gigabyte nVidia GTX660 GPU -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org