Dual Boot. Replaced OS. Grub not working

The stuff quoted is just for some context. Actual trouble down below

I have a post on reddit in which I asked some advice for replacing Ubuntu with Manjaro in dual boot mode with Windows 10
From Reddit Post:
Here's the scene:

My computer currently has Win 10 and Ubuntu 18.04 set to dual boot.

I want to replace Ubuntu with Manjaro, so here's the question:

Is it safe to wipe out Ubuntu and to replace it with Manjaro via the Manjaro Live USB installer, and if so would the GRUB Boot-loader configure itself to adjust for the new OS or would it be deleted along with Ubuntu?


Should I create a new partition for Manjaro, install it so GRUB recognizes 3 OS's then delete Ubuntu?

From my understanding of GRUB (correct me if I'm wrong), it is installed within the Ubuntu partition in /boot/efi , What is the safest approach?
Currently, I've managed to reformat the partition in which Ubuntu used to be in and installed Manjaro.
The problem I'm currently facing is that I am unable to boot into Manjaro. When I try to reboot my computer, instead of the GRUB menu showing me options to choose which OS to boot, the GRUB terminal pops up

a lot of time has passed and now I'm up to this stage
I've stumbled across this thread and followed the guide.
I am unable to boot into the grub menu when I reboot my PC, instead it directly boots into Windows.
By following the guide I've managed to boot into Manjaro
I'm up to " If problem persists (or if unsure what to do)" so here is the following output of the commands

efibootmgr -v
EFI variables are not supported on this system.
sudo parted -l
Model: ATA WDC WDS240G2G0A- (scsi)
Disk /dev/sda: 240GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End    Size    File system  Name                          Flags
 1      1049kB  556MB  555MB   ntfs         Basic data partition          hidden, diag
 2      556MB   660MB  104MB   fat32        EFI system partition          boot, esp
 3      660MB   676MB  16.8MB               Microsoft reserved partition  msftres
 4      676MB   114GB  114GB   ntfs         Basic data partition          msftdata
 5      114GB   240GB  126GB   ext4

Model: ATA WDC WD10EZEX-08W (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name                          Flags
 1      17.4kB  16.8MB  16.8MB               Microsoft reserved partition  msftres
 2      16.8MB  1000GB  1000GB  ntfs         Basic data partition          msftdata

Model:  USB DISK 2.0 (scsi)
Disk /dev/sdc: 7743MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system  Flags
 2      2535MB  2539MB  4194kB  primary               esp

sudo blkid
/dev/sdb2: LABEL="1TB" UUID="78FE1BC5FE1B7A98" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="9fff0f95-cfac-4a5d-8551-42e90e776d3f"
/dev/sda1: LABEL="Recovery" UUID="A08ECA9C8ECA69FC" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="78d6ef4c-a83d-4859-b011-385ec093a2ba"
/dev/sda2: UUID="EECB-0051" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="c08ff853-209a-4fcf-8beb-3f67d25ce0d7"
/dev/sda4: UUID="B236CE5F36CE23E7" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="f915c341-af86-4c92-94fa-96b6103aea8b"
/dev/sda5: UUID="2b843cd0-070a-4bf0-a144-657fccc70d4e" TYPE="ext4" PARTUUID="0e84c364-ff13-4367-b626-a62dedff6212"
/dev/sdc1: UUID="2019-12-29-08-55-40-00" LABEL="MJRO1815" TYPE="iso9660"
/dev/sdc2: SEC_TYPE="msdos" LABEL_FATBOOT="MISO_EFI" LABEL="MISO_EFI" UUID="8F62-2FB4" TYPE="vfat"
/dev/sdb1: PARTLABEL="Microsoft reserved partition" PARTUUID="a8b835b5-d5f3-4ec1-a43c-271175042548"
/dev/sda3: PARTLABEL="Microsoft reserved partition" PARTUUID="2f03d05c-09fe-439c-a52c-dbc40bdf8c30"
findmnt -s
TARGET SOURCE                                    FSTYPE OPTIONS
/      UUID=2b843cd0-070a-4bf0-a144-657fccc70d4e ext4   defaults,noatime,discard
/tmp   tmpfs                                     tmpfs  defaults,noatime,mode=1777
findmnt /boot/efi
*(No output)*

Computer is custom made:
CPU: Ryzen 5 2600
GPU: GTX 1070
MB: gigabyte a320m-hd2

Any help would be appreciated!

  1. Your disk is gpt
  1. You did not install in uefi...
    a. No /boot/efi entry in fstab.

b. Not booted in uefi

efibootmgr -v
EFI variables are not supported on this system.

What you can do now... either [A] or [B]
A. Fix it.
Boot up installed OS in uefi
(important - you have booted OS in bios-legacy, now boot in uefi)
make fstab entry for a partition as /boot/efi
mount that partition as /boot/efi
sudo grub-install
sudo update-grub
And do the 2 additional UEFI commands as stated in that link.

B. Or reinstall, in uefi.
Making sure you boot install media in uefi.
Select the fat32 partition as mount point /boot/efi.
Do not format this $esp partition!
And since you have installed (partially but wrongly) you do not need to format the root partition either.
The installation will go very fast and much easy.

ps: Suggest you read the wiki on uefi installation.

1 Like

Booting in UEFI doesn't seem to work for me. I followed the Complicated guide but only to be met by a blank black screen.

for option [b] I am unable to mount /boot/efi without reformatting it (custom install). Is there something wrong with the installation or am I misinterpreting it? (Does the mount point not get formatted?)

Or if I replace the partition (in installation), I get the option "The EFI system parti
tion at /dev/sda2 will be used for starting manjaro" is this the option I should pick?

In all your boots, manjaro installation, live media, boot from install media boot menu...
You have started your system in bios-legacy, not uefi.
I think you have difficulty because your bios is set to boot in bios-legacy, not uefi.
Go to your bios set up (usually F2) and see if there is anywhere (probably 'boot' section) where you can set all your boots (including usb boots I think that's that area where usb boots are not uefi) to only uefi. If you fail to see anywhere in your bios, go to the manufacturer website and check how to do it.

And in that link, there is a way to check at grub prompt, if your install media is started in uefi.
grub> echo $grub_platform
Did you check with this ?

I checked that yes. I was able to boot into UEFI from the live installation but unable to boot into the installed installation by following the same instructions from that guide.

Nevermind. I was able to fix it following [b].
I booted into windows from the BIOS and deleted /dev/sda5 partition

I then booted the live USB in UEFI mode (I previously have booted and installed it in legacy) and chose the replace partition option (this was me assuming that when it said mounting at /dev/sda2 was /boot/efi and hoped it didn't get reformatted) and installed.
Rebooted and was greeted by the BIOS

Good you got it fixed.
The reason you could not fix it using the link is that after booting up, you need to make an entry in fstab and then mount that as /boot/efi before doing the commands.

But nevermind, its fixed, and that's all that matters. Cheers, take care.

The last time I did this, I used gparted from the LiveUSB, completed reformatted the entirety of the Linux distro to unallocated HD space, and then ran the installation installer, and chose to install the new distro onto the unallocated partition.

Although it seems that you've also gotten another answer, but in theory (or at least historically) this also works if you're still looking to give it a go. It's much easier to install a distro on unallocated space, than it is to install it, delete and then reallocated the space again since it would end up moving directories and important stuff.

I hope it helps!

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