# Can grub on ubuntu partition prevent BSD booting?



## kazLSE (Apr 6, 2014)

I am experimenting setting up a triple boot system on an old Macbook pro (2008) consisting of OS X, Ubuntu and FreeBSD, as a way to learn more about installing unix/linux system (since I don't have much experience in this area, as you will be able to tell from my question below . 

I started out by creating two new partitions in OS X's Diskutil to install Ubuntu and FreeBSD, along with setting up rEFIt. 

After installing Ubuntu on the second partition, I attempted to install BSD on the third partition from a flash disk. It seemed like it would be going well when I started the mac with the flash driver attached, as the rEFIt menu showed a third option with the Beastie logo and the flash drive as a sub icon. However, when I clicked on that option the screen goes dark for a while but then shows me again the GRUB menu from the ubuntu partition, with only the ubuntu and mac options displayed.

Here's my *first question:* is it possible that my ubuntu partition is preventing me from starting my FreeBSD installer due to a mistake I did in the setup of the partitions? 

In any case I then attempted to remove the ubuntu version as I was suspecting the answer to the above is yes. Via diskutil I merged the last two partitions and formatted them. So now my macbook disk has only two partitions: the os x partition and an empty one.

When I restarted my mac I could still see the ubuntu logo in the rEFIt menu, suggesting that the system still didn't see that I reformatted the ubuntu partition, however this time I could start the FreeBSD installed by clicking the BSD logo as it didn't take me to the GRUB menu. 

Here's my *second question*: what is the correct way to delete the ubuntu installation so that it would no longer show it in the rEFIt menu?

However, after completing installation of FreeBSD (which seemed to have went smoothly), I still couldn't see any new options on the rEFIt menu, and understandably even though I could see the Ubuntu option I am unable to log in, as it give me an error when I choose it.  

My *third* question: Why couldn't I see the FreeBSD option in the rEFIt menu, even though the FreeBSD installation seemed to have gone smoothly?

Any illumination on what I did wrong in the above process or related insight on the partition/booting mechanism that would explain the above will be most welcome.


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## Chris_H (Apr 7, 2014)

Greetings, @kazLSE.
I'm going to go out on a limb here, as I don't have any _recent_ experience with a Mac. But _do_ have quite a bit of experience installing FreeBSD, and some _very_ recent experience dicing up a couple of disks, for installation. Hopefully @wblock@, whom I would consider the resident "disk expert" will chime in, and correct me, should I be _mis_informing you in any way. 
That said; from my personal experience, _do_ attempt to avoid Grub, if at all possible. A couple of reasons I suggest this.
1) Adds additional variables to your installation, and disk setup/layouts. Which is _not_ going to make your tasks (current, or future) any easier.
2) Requires you to learn additional installation / maintenance tasks, and syntax that _isn't_ required to install Linux, _or_ *BSD.
3) While Grub professes to make multi-os install/selection easier. Unless, or Until you learn Grub intimately, it will only make it more difficult.
That said. You should probably attempt to utilize that which your _current_ OS (Mac) already provides (UEFI?), unless that option looks bleak. FreeBSD _does_ provide for UEFI, and I saw some discussion on one of the FreeBSD mailing lists, just yesterday regarding it. I'll post links to it here, when I find them.
The reason you are still seeing the Grub menu, is because Grub installed itself into the MBR. You will probably do well to seek the man() pages for gpart(). As well as the FreeBSD handbook: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/; specifically Disk Organization (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/disk-organization.html), The Booting Problem (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/boot-introduction.html), and the Storage section: Adding Disks (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/disks-adding.html), and perhaps Resizing and Growing Disks (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/disks-growing.html).
Point being; gpart() is your friend here. Once you get familiar with it, you can conquer almost any install problem with it, once you get a feel for it.
I'll try to get some more _specific_ answers for you. But, until then, wanted to give you some pointers that I think might give you a "leg up" on what you're currently dealing with.

HTH

--Chris

UPDATE: The following links seem as they might also provide a solution for installing on a Mac:
https://forums.freebsd.org/viewtopic.php?f=4&t=45768
http://forums.freebsd.org/viewtopic.php?f=4&t=40941&p=242442#p242442
the whole process described:
https://glenbarber.us/2011/11/12/Dual-Booting-OS-X-and-FreeBSD-9.html


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