Booting Ubuntu from External Firewire Drive?

[Littleodie914]

Hey guys, I'm trying to install Ubuntu onto an external firewire drive, but I can't get it to boot properly. I have rEFIt installed, but every time I try to boot the external, I get a black screen with some yellow error text on it, and something about how the Mac firmware doesn't properly support booting from external drives.

Is there any way to get this to work? I don't really worry about any partitioning, I have a full external drive that I'm planning on dedicating to Linux.

 

[mkrishnan]

Hi Odie,

I'm a little confused about what you're trying to accomplish. What exactly is on this external drive? Does it just contain Ubuntu or does it contain something else besides Ubuntu? If it just contains Ubuntu, I don't completely understand why you're even bothering with rEFIt. See...

http://refit.sourceforge.net/myths/

If it contains Ubuntu, the most straightforward and fully compatible solution is probably to just format the disk with an MBR partition scheme, use grub, and let it boot in BIOS compatibility mode.

 

[Littleodie914]

Hi Odie,

I'm a little confused about what you're trying to accomplish. What exactly is on this external drive? Does it just contain Ubuntu or does it contain something else besides Ubuntu? If it just contains Ubuntu, I don't completely understand why you're even bothering with rEFIt. See...

http://refit.sourceforge.net/myths/

If it contains Ubuntu, the most straightforward and fully compatible solution is probably to just format the disk with an MBR partition scheme, use grub, and let it boot in BIOS compatibility mode.

All it contains is Ubuntu. I just can't figure out why it won't boot properly.

When I boot from it using the standard boot camp menu (holding down option) then it skips to the next available "bootable" thing. (Ends up being my Windows partition on my internal drive.)

When I boot it from the rEFIt menu, I get the black screen with the error message stating that most Macs don't have adequate support for booting legacy OS's off external drives.

What should my "optimal" procedure be? Should I let Ubuntu partition my drive for me? If I instead use Disk Utility to partition the drive, what should the partition map be? Should I install a boot loader?

These are the kinds of combinations I figured would be quicker solved by asking than by trial and error.

 

[mkrishnan]

I think I might know what's going on now... This might be the problem: you should be able to let Ubuntu just partition and manage the disk, but it's possible that the disk isn't bootable, and Ubuntu doesn't fix this. I think you can fix this by using disk utility to format the drive as a bootable MBR-based single partition (there should be an option in there somewhere for making it able to boot on Windows computers or something like that), and then let Ubuntu partition the drive as it pleases or as you please, and then with the proper MBR, it should give over to Grub and boot the computer up.

See the last reply here: https://forums.macrumors.com/threads/598291/

 

[Littleodie914]

So if I use MBR for the partition "type", when Ubuntu does all of the individual partitioning later, it won't actually modify the MBR? It will just create the right partitions?

And also, is it required to install a boot loader onto the drive? I assume if you were installing onto drive sdb, you would put the boot loader onto sdb? (As opposed to the partitions sdb1 or sdb2, etc.) Thanks!

 

[mkrishnan]

So if I use MBR for the partition "type", when Ubuntu does all of the individual partitioning later, it won't actually modify the MBR? It will just create the right partitions?

And also, is it required to install a boot loader onto the drive? I assume if you were installing onto drive sdb, you would put the boot loader onto sdb? (As opposed to the partitions sdb1 or sdb2, etc.) Thanks!

I think that your problem is in there somewhere. As I understand it, Ubuntu will install a bootloader (grub) but you have to have an MBR that is set up for booting first, and if it is not, the Ubuntu installer will not notice or fix that (which is kind of silly, but I guess they figure you'll be installing it on your internal drive? I could be wrong about this but I feel like I've encountered this issue when trying to make bootable USBs and so on). You need to do one of the following:

1) Have the disk be bootable and have a bootloader on it, and then boot off it by using the option key at boot time. This does not require modification of the boot sector of the main disk (your internal drive). So, if the partitions are on sdb, yes, you set up sdb (and not sdb1 or sdb2) to have a bootloader, and then grub has to point to the right partition in it.

2) Have a bootloader on your internal disk that is set up to multi-boot (e.g. with rEFIt), in which case it does not matter what is in the boot sector of the external disk, but you do have to modify your internal disk's boot sector and make sure that the loader you use for Ubuntu looks for Ubuntu on the right disk.

Sometimes, you run into problems where Grub is set up incorrectly and so it's looking for Ubuntu to be on the wrong drive. However, if this happens, then you should, I think, get a black screen with a text mode error message from grub, not the OS X boot menu coming back up. So I think you're not even at that stage yet, and grub isn't even being activated.

I would personally go with option (1), as it's much simpler, and I think the issue is just that the disk is not bootable and so the bootloader never gets activated.

 

[Littleodie914]

Here's what I tried:

1) Partitioned my external into 200GB for Mac, 100GB of free space, which I then partitioned into the usual swap, home, and root partitions for Ubuntu. I also set the 'type' to be MBR.

2) Installed Ubuntu. I installed the bootloader onto the volume, at sdb. (The partitions were sdb1, sdb2, etc.)

3) Attempted to boot using rEFIt, but got the error message: "The firmware refused to boot..." etc. Same thing I got before.

Any ideas?

Edit: Check the post here. Pretty much sums up the problem I'm having.

 

[mkrishnan]

Hmmm... try the community guides. If you really need to introduce rEFIt into the equation, it looks like there's an issue with the stable release version that prevents it from working (if I understand, they suggest using a pre-release version?).

What happens when you try to boot off it using Apple's boot menu (option key) instead of rEFIt?

 

[Littleodie914]

What happens when you try to boot off it using Apple's boot menu (option key) instead of rEFIt?

It just boots into my internal Windows partition.