How do I reload the boot set up for my Ubuntu install?

  • Macbook Pro 2009
  • OS X El Capitan
  • Ubuntu 16.04

This computer was booting to Ubuntu, but stopped after a user was added in OS X.

Now it only boots to OS X, and Ubuntu does not show up on the EFI menu (alt/option pressed at start up).


I read in another post about a command called "bless".

What would that do?


PS: I am a noob. Please, simple instructions would be super rad.

  • bruce, can you boot into grub ? – Yvain Aug 21 '19 at 22:49
  • you have a boot menu that should let you access the bootloader by pressing 'c' here you can fix this or at least try – Yvain Aug 21 '19 at 22:53
  • I don't know how to access grub. Grub only shows up on this Mac when Ubuntu is already set up to start up correctly and then something has gone wrong with Ubuntu – 813bruce Sep 4 '19 at 16:15

1 boot your pc and wait for the boot menu selection to appear then press 'c'

2 enter these commands:

root=(hd0, 0)/

kernel=(hd0, 0)/vmlinuz-4.10

(whatever the kernel is, use autocomplete to find out > tabulation twice) you have hard drive partitions so be carefull when setting the paths because hd0 represent the disk itself and 0 is the partition so maybe ubuntu is on the second one (they are numbered from 0)

3 now that the root system is defined and that the kernel is loaded, enter 'boot'.

If it happens that the system is broken you will see it now. If it boots fine you'll be able to access the ubuntu terminal and issue the command 'install-grub' which should fix your issue. Cheers.

  • Will this work on a Mac? I only ask because I am doing a little unrelated work using a LiveUSB and can't restart yet – 813bruce Sep 4 '19 at 16:19
  • Never proceed during boot up with a live USB with persistence on a Mac. I've just spent the day trying to figure out how to fix my Mac persistent live USB without having to remake it. Pro tip remake your Mac persistent live USB because you were not going to be able to save anyting – 813bruce Sep 4 '19 at 23:12
  • Never proceed with holding C down during boot up it's supposed to say – 813bruce Sep 4 '19 at 23:20

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