removing GRUB from sda

Hi,

i ran into the exact same issue (lesson: never install Ubuntu late at night..).

Did you resolved this?

thanks.

This is supposed to restore the default bootloader without harming your partitions:

Terminal hold c booted from OS X install DVD

fdisk -u /dev/disk0

You might have to mess with disk0 to disk1, disk2 etc.

at your own risk, but your used to that. 🙂

Thank you for your quick answer, i did run this command line from a terminal windows a few minutes ago (with disk0) and it worked for one of the entries : "Boot Linux from HD" that was in the corrupted MBR if i understood well.

but i still have the entry for the Grub i installed by mistake on the EFI partition : "Boot EFI\ubuntu\grubx64.efi from EFI".

If i find a solution for this one, i'll post it here. 😉

Try this

get your firmware here

https://support.apple.com/kb/HT1237

install it following this

https://support.apple.com/kb/HT2213

next look at this undocumented feature

https://pubmem.wordpress.com/2011/04/09/flash-efi-firmware-update-manually-on-a- macbook-51/

not to savvy about flashing firmware, risk is all yours

I finally resolved the problem in two steps.

Step 1 : remove "Boot Linux from HD"

you have to run the following command from a terminal window:

fdisk -u /dev/disk0

As ds store said, the suffix number might change depending on the configuration, apparently for a Macbook pro 5,4 with one disk, 0 seems to be the good guess

Step 2 : remove "Boot EFI\ubuntu\grubx64.efi from EFI"

This one is a bit more tricky, surely there is another way but this one is simple and not so risky

1- burn a GParted Live CD iso

2- boot on the GParted live CD (press alt on boot and wait for the CD boot option to appear) and choose the first boot entry

3- during the boot process accept every option with its default value

4- in GParted select the EFI partition and somewhere in the menus select the "flags" entry and uncheck "boot"

5- exit GParted Live CD and boot in Mac OS

6- a new volume has appeared "/volumes/efi"

in the finder go to "/volumes/efi/EFI" and delete the "ubuntu" folder

7- repeat steps 2/3 and step 4 but check "boot" instead of unchecking it

8- exit GParted live CD and reboot

9- enjoy 🙂

hope this will help someone in the future as i spend some time on it!

thank you, we crossed posted 🙂

I was able to do it without flashing, this word "flashing" always creeps me out!

good one, will make a note of it.

thanks 🙂

I made the same mistake and installed grub2 to /sda (instead of /sda4, for example) using the Ubuntu installer. Much simpler (and far less risky, IMO) than all the above – so long as you are willing to remove all your partitions except your original OSX partition, and you have a mac that supports Boot Camp – is:

1) using gparted (on Ubuntu Live CD) remove all other partitions (/sda3, /sda4, etc. – keeping /sda1 = EFI and /sda2 = Macintosh HD)

2) now, if you hold down the option key when booting, you should have the option to boot from OSX or Windows (just as if you had used boot camp)

3) use the Boot Camp Assistant (on your original install discs or can be downloaded from apple, depending on your operating system) to remove Windows.

Tada!

This was only tested using OSX 10.6.8 (snow leopeard) but I presume should work for any mac that supports boot camp.

Also, using rEFIt (google it) I found much more straightforward than manipulating the EFI directly. Just make sure you install grub (bootloader) on /sda4

Apologies, the above will not fix the display by rEFIt of the linux boot option under /sda, after all.

People, more faster and safer solution.

Boot OSX and in the terminal write:

mkdir mnt ; sudo mount -t msdos /dev/disk0s1 mnt

Will show a new drive EFI

open this drive and open the folder EFI. Inside you will have the folders APPLE and UBUNTU

just delete the UBUNTU

restart and enjoy !!!!!!

Hi,

I just did a similar thing. I was building a portable hard drive for recovering systems. OSX was installed and happy, so I added Ubuntu. Although I selected the portable as the drive to install everything on, it installed GRUB on the portable, but told that macbook that it should use GRUB from the portable! So without the portable, I couldn't boot at all (holding down option still worked).

I "kinda" followed mikelikesbikes advice and just changed the startup volume. (Didn't want to delete and re-install bootcamp or the recovery).

And presto, it booted straight into OSX like it should have.

Going to stick to dedicated recovery CDs for windows/linux boxes now.

ps. I don't use refit or any other bootmanager, so am quite happy from left over rubbish to hang around. (As long as I can't see it 🙂

Fab! Many thanks, BigLuiz!

Have been test-driving a couple of versions of Linux Mint alongside OS-X. Decided to try something else so deleted the partitions through Gparted and was then left with the Boot EFI\LinuxMint\grubx64.efi from EFI when booting through Refit. (Yup, I'm someone else who does these silly things late at night!)

MacBook Pro 7,1 / OS-X 10.6

Much thanks BigLuiz... very simple fix and worked perfectly.

Thank you very much! you saved me 😉

Very easy, just mount the EFI partition and remove the grub/ubuntu folder!

When in -Recovery From Internet- it is impossible to use mkdir, but you can "cd /tmp" and mount it there.

Thanks again!

Thank BigLuiz - this worked for me too!

My problem was less severe: I just got the GRUB shell when booting, typing "exit" would continue the boot. But, that's annoying. Following BigLuiz' directions fixed it. I haven't tried re-writing the MBR using fdisk -u, and since I try very hard not to break my Mac (it being what I use for work), I'll probably just let alone since I don't intend to dual boot on it (I was just installing Ubuntu from a USB drive to another USB drive).