Command Line - Change start up disk

[maccab]

I need to change the start up disk to be a different disk instead of my OS X disk.

OS X cannot see the disk I want it to use.

I cannot change the start up disk back in OS X's settings.

How do I use the command line in OS X to fix it?

• 2009 Macbook Pro
• OS X El Capitan

 

[DeltaMac]

What system is on that different disk?

How are you booting to that different disk now?

 

[maccab]

Ubuntu 16.04

It booted straight to Ubuntu until a tech added a user on OS X.

Now it boots straight to OS X.

I installed Ubuntu and OS X like this:

• Partition drive
• Install OS X
• Install Ubuntu

Doing this lets the computer boot straight to Ubuntu.

OS X is then accessible through the menu when you hit option on start up.

 

[DeltaMac]

Ubuntu 16.04

It booted straight to Ubuntu until a tech added a user on OS X.

Now it boots straight to OS X.

I installed Ubuntu and OS X like this:

• Partition drive
• Install OS X
• Install Ubuntu

Doing this lets the computer boot straight to Ubuntu.

OS X is then accessible through the menu when you hit option on start up.

I bet that "tech" did more than just add a user. Whatever was done probably messed up the Ubuntu boot software.
Somebody that knows about uBuntu may be able to help you get the uBuntu boot volume to show up again.

 

[maccab]

Surprisingly, it was from something as low level as creating a new user in the Settings panel of OS X. I was sitting with him.

Linux boards say they can't fix it, so I have been looking for places that know about OS X's command line.

Do you know any other places where people dig deep into OS X?

 

[DeltaMac]

I doubt that your fix is in OS X (somewhere)
Your 'Tech' inadvertantly messed up the boot software for Linux/Ubuntu.
THAT'S what needs to be fixed, probably with a Ubuntu reinstall, or even removing that partition, then installing from scratch. Hopefully, you won't need to do that.
But, a linux/Ubuntu support forum should be able to help you fix the boot software on your Ubuntu partition (you should ask about reinstalling the boot software, whatever Ubuntu is currently using. THAT should be your ticket.

 

[maccab]

Damn, but thanks. I was hoping I wouldn't have to reinstall, but to be able to get desktop files and browsing history that is on there.

You are the second Mac forum to tell me this, so I put a topic up on the Ubuntu forum. I might have to start posting elsewhere as well.

Somehow, changing the amount of users does the same as installing Ubuntu first and OS X second. It is surprising how strong but fragile this way of installing is.

Thanks again.

 

[MacUser2525]

Damn, but thanks. I was hoping I wouldn't have to reinstall, but to be able to get desktop files and browsing history that is on there.

Then boot the installer of Ubuntu run a live session and mount the partition containing the install and copy all the /home/username files/entire directory to a safe place. Re-install your ubuntu before the option to restart to finish, mount the new install partition and copy back the entire saved ~ directory and it will be all there when you login again. You will be back where you were allowing the option to select OSX and just booting ubuntu like before.

 

[DeltaMac]

The problem that you have is not OS X. It's the Ubuntu. Something happened to it, and it may or may not be coincidental to added user in OS X.
(and now that you know how simple it is to add a user account to your Mac system, maybe you can avoid taking it to a third party tech next time --- Just sayin' )
and, I have provided virtually the same posts to the other forum where you posted, so you might want to take my suggestion with a grain of salt. I have played around with Ubuntu, but never got into a situation where it wouldn't boot. The boot software that Ubuntu uses, as far as I know, is what provides the access to the Ubuntu partition from the Mac. If that gets messed up, then you have to find out how to repair or reload that software. It has nothing to do with your Mac software. It's purely in the setup of the Ubuntu system, and that's where you need to go to fix it. I can't help you do that, as I just don't have experience with that.
Good thing would be to search on a linux or Ubuntu board for something like "Repairing a Ubuntu system that has stopped booting"

Looks like MacUser2525 beat me to the point with some actual useful information that will help you

 

[MacUser2525]

Good thing would be to search on a linux or Ubuntu board for something like "Repairing a Ubuntu system that has stopped booting"

Looks like MacUser2525 beat me to the point with some actual useful information that will help you

Yes I try to do not always succeed though. The idea to search for would be Grub chroot install. This would be where you boot the live cd/dvd then mount the / of the install on the computer and bindmount the /proc /sys and other needed directories so you can chroot (change root) to the install, then run the commands to reinstall that piece of junk grub. I say this as before I used to do this all the time with LILO which never failed but with the change to that garbage, I have never succeeded with a re-install of grub this way in all the years of use since then. I have managed it when you can boot the system but never with an unbootable one. It is always a reinstall for them after saving the data needed for a copy over to new install.

 

[maccab]

Then boot the installer of Ubuntu run a live session and mount the partition containing the install and copy all the /home/username files/entire directory to a safe place. Re-install your ubuntu before the option to restart to finish, mount the new install partition and copy back the entire saved ~ directory and it will be all there when you login again. You will be back where you were allowing the option to select OSX and just booting ubuntu like before.

I got all the files by doing that after I read this.

Now I am going on to Firefox/Mozilla boards to see if I can find where the files that will give me my extensions and browser history are.

_
DeltaMac, it is definitely an issue where a change to OS X, either installing it after Ubuntu or changing the amount of users in OS X, messes up my unorthodox boot system. But writing this just gave me an interesting idea.

_
I may be able to have the system see the Ubuntu partition as a flash drive.

Then I can start Ubuntu using the Startup Manager while the computer boots straight to OS X instead of into Ubuntu like I had it set up.

You can run a full version of Linux off a flash drive. In fact, you can do OS X, but OS X really does not like it. Slooooow.

_
Thanks for all the help, guys.

 

[MacUser2525]

Now I am going on to Firefox/Mozilla boards to see if I can find where the files that will give me my extensions and browser history are.

Should be in the profile that was copied as part of your file procedure. Or if having a Firefox account like I do then it will be synced and restored when you log into your account from within Firefox. At least that is what it did for me last night on my Kubuntu install on my laptop when I signed in on it for first time on fresh install. It was all there with the exception of a couple of extensions that were no longer maintained thus removed from the extensions site..