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Different live-cds shipped grub2 are not compatbile
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Roman_Gruber
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Joined: 03 Oct 2006
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Location: Austro Bavaria

PostPosted: Mon Sep 12, 2016 7:19 am    Post subject: Different live-cds shipped grub2 are not compatbile Reply with quote

Here is my scenario. Warning a bit of a rant and a big wall of text.

For some reason my ASUS G75VW notebook forgets on a random occasion its UEFI entry for my boot environment. Its gone and I am greeted with the UEFI, I call it BIOS setup, screen.

My workaround for this is to use the same, identical, live-cd from sysrescue-cd from September 2015 and reinstall my grub with

A prerequiste and will not be mentioned again, move existing /boot folder of the live-cd to /root/boot. Than create new /boot directory and mount /dev/sda2 which it seems to be vfat 128gb grub partition, gpt partition, to this fresh created /boot folder.

Code:
grub2-install --efi-directory=/boot/EFI
.

--

As I was visiting someone and I did not had any live-cds with me but a smartphone and a usb-cable, I installed drivedroid and mounted and tested the following images: gparted livecds, sysrescue-livecds, linux mint livecds, fedora core livecd workstation. All recent versions.

Some images could not boot because the drivedroid apk, could not convert the iso and mount it. One debian based live-cd did not find any input devices, no keyboard, no trackpad and not freshly plugged in generic usb mouse. One live-cd did only have grub-install but not grub2-install but was rahter large 1.8GB.

I tried always several parameters with grub-install or grub2-install.

As I came home, I booted up fedora-core worstation image and typed from the cd-case of my sysrescue-cd the identcial command to restore my grub2 UEFI boot record. Nope error message, although it claims to be grub2.

Whats the most annoying thing is that grub2-install or grub-install, i used both on different livecds booted from my smartphone, so it emulates a cd-crom or usb pendrive, never worked. I provided the folders as needed but nope.

Conclusion, or assuption, as Its a bit tricky to prove as of now:
----
grub-install and grub2-install are not compatible to each other regardless which version in use, they do not check with which version teh boot entries were created, just stupid scripts which throws random error this or that file not found, although the folders were specified as needed by the manpage.
There is also the flaw that the syntax for grub-install and grub2-install looked to me familiar and therefore I used grub-install instead of grub2-install, as I should have with the correct grub2-install version from my live-cd. Its rather impossible to find a live-cd with the same shipped grub2-install which I used when you are not aware of that.

Not every iso cd-rom image is not bootable via drivedroid. There are no USB images available, as I always saw on how to set up your pendrive with a cdrom iso image. There may be some but I could not find any in a reasonable time. Googling for usb live images is worthless as I always went to a howto convert a cdrom image to a usb image.

---

Different live-cds / fedora core workstation greeted me with messages like could not find EFI, than i provided the efi-directory, could not find module ... this and that, and I tried to provide it.

I will do a backup soon and swap out the drives and can test than any suggestions regarding reinstalling grub2 with any other live-cd from my smartphone

--

Any hint / advise why I failed in my attempt on reinstalling grub2 with fedora-core workstation with grub2-install with teh same procedure which works on my sysresuce-cd downloaded in september 2015 which is gentoo based?
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Buffoon
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PostPosted: Mon Sep 12, 2016 1:14 pm    Post subject: Reply with quote

My understanding of UEFI is you do not need to reinstall Grub all the time, all you need to do is to restore efivars pointing to Grub.
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Roman_Gruber
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Joined: 03 Oct 2006
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PostPosted: Wed Sep 14, 2016 9:58 am    Post subject: Reply with quote

Buffoon wrote:
efivars pointing to Grub.


Exactly. For some reason I can only do it with that particular sysrescuecd dating back.

Where you draw the line of reinstalling grub or the pointer is up to discussion. Not that important for myself, as I have not checked those grub2-install script...
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