What is the need for BIOS GRUB? and should I have it as well as EFI partition?

[swarfendor437]

I must start reading more but not come across BIOS GRUB as an option in another distribution - I must have had a corrupt image burn of the other OS as I could only see BIOS GRUB and no EFI until I burnt another DVD. When I did make an installation of a BIOS GRUB I got this element at the top of the boot order list and no distribution found - is there any online source as to when this partition should be utilised? Does an installation need to have both BIOS GRUB and EFI? I only discovered the EFI installation on a different OS (also a fork of Debian) which gave a reminder during install that I hadn't created an EFI partition and also advised what size to make it (35 Mb). Loving the simplicity of it all.

[paxmark1]

A good rule of thumb is only one grub on sda mbr.  I believe you need to read up more on uefi in general

The amount of good, usable  information you provide is close to zero. 
Make sure you are looking up grub2 and not grub, quite older sources still out there.
Using only one os, you do not even need grub2

How old is the motherboard (uefi or the old bios)?
How many hard drives?
How many operating systems and name them specifically - i.e. Distro Name, Version, Architecture?

The out put of "inxi -Fxx"   would give us that easily, mark that output up as code.  Use the # button.  Preview will confirm
 
How to check for a corrupt .iso - dvd is in the Sparky wiki and many other places.

added  this might help  problem might be in os-prober.  The following post shows how to give good information
https://forum.siduction.org/index.php?topic=7669.0
special notice to unklar   -  unclear
 

This chaos in your configuration is actually caused by the fact that both os-probers are
active and "write off" one from the other, and vice versa.    ???   At the DU; in the kernel update; Grub update.

[swarfendor437]

Hi paxmark1 and thanks for responding. I have only seen GRUB for BIOS in the Gparted within the installer of Zorin 15 Beta which is a derivative of Ubuntu 18.04.2. When I install any new OS I install it on its own drive and always do a manual install for the following: 'efi', '/', '/home' and 'swap'. Now in the Alpha release of Zorin 15 I could see 'efi' partition naming but not the GRUB for BIOS. As I did not see 'efi' option in the partition element of the installer I wrongly assumed that the GRUB for BIOS was a rename of the 'efi' partition labeling at point of install. Also, just to add, I always disconnect all drives apart from the one I am installing to. The Motherboard was a recent purchase but based on BIOS information it was produced in 2016, an Asus PRIME X470 - PRO to which I installed a Ryzen 7 1700X Processor and 16 Gb of Corsair Vengeance RAM. In the Asus EZ-Mode of the BIOS there is a boot order frame bottom right of screen the hard drive with Zorin 15 Beta it stated the first device as Ubuntu GRUB, with the same device listed lower down with the the entry for drive being make and model of the drive with same identifier. Hope this clears things up fot you.

[paxmark1]

So disconnecting the drives is a definite way to not overwrite.  However, the installation of grub2 will not see the other drive.  2016 - you are uefi

As root  "update-grub2"  or "sudo update-grub2" will let grub2 see the other partitions.   Might work, should not harm anything

Once you get one working system please install inxi and then post output of "inxi -Fxx"

Presently I have 2 grub2's but that is because one drive will be the new Stable and lvm later, and the other 3 y.o drive has stretch. So the asus EX mode of what is actually the uefi (but still often called bios)  only detects one OS from startup?  And both hard drives are connected? 

Run on sentences with no paragraphs is harder to read. 

Maybe try some grub2 and uefi videos on youtube. 

[kanliot]

swarfendor437, would you mind restating the problem you're having now (Late Sunday)

There's two modes for Grub installation (secureboot and without secureboot) because after UEFI firmware replaced the BIOS (Thanks IBM for making hardware incompatible with BIOS) , having the firmware load up Grub on your hard disk became much more technical. 

[swarfendor437]

swarfendor437, would you mind restating the problem you're having now (Late Sunday)

There's two modes for Grub installation (secureboot and without secureboot) because after UEFI firmware replaced the BIOS (Thanks IBM for making hardware incompatible with BIOS) , having the firmware load up Grub on your hard disk became much more technical.

Hi, I'll take a screenshot of the BIOS (if the entry is still there, and a Virtual Box image of Zorin's GParted during install at some point - it's getting late.

[kanliot]

actually it was just hard to read your posts because of long sentences.

https://help.ubuntu.com/community/UEFI#Creating_an_EFI_System_Partition

My secureboot is actually kind of messed up right now since I installed Windows10 with secureboot and sparkylinux without it.