This page is written using a rather elderly bit Mac Mini as a reference, and using Ubuntu Developments in the last year have rendered certain of the procedures on this page sub-optimal. I've tried to point these out, but I haven't fully researched better replacements, and I lack the modern hardware on which to test some of the better methods on more recent bit Macs. Thus, you may need to deviate from these instructions on modern computers.
The Problem When installing Ubuntu Linux on an Intel-based Macintosh, most people follow any of several guides available on the Internet, such as this Ubuntu document. Most of these guides, however, rely on features of the Macintosh that are intended to enable it to boot Windows. BIOS emulation is expedient, and it's the only way that most versions of Windows can boot directly on a Mac, but it's got several drawbacks: Longer boot times—BIOS emulation is widely regarded as slowing the boot process.
I've not tested this effect myself, so I'm not sure how significant it is. Reduced graphics card flexibility—On some models with multiple graphics chipsets, you can't select which chipset to use in BIOS mode, but you can in EFI mode.
My own Mac isn't one of the affected models, so I can't comment further on this issue. The trouble is that hybrid MBRs frequently cause problems. In fact, even the Ubuntu installer often gets it wrong; it tries to be helpful by creating a hybrid MBR, but depending on your partition layout, it can create a partition table that the popular libparted-based partitioning tools won't touch. If you don't use these features, you won't see their problems.
I've seen numerous problems reported at the Ubuntu Forums related to Ubuntu installations on Macs with hybrid MBRs, and more problems with similar configurations elsewhere. See my hybrid MBR Web page for a technical description of what they are and what can go wrong with them.
In short, they can get out of sync, cause confusion about which partition is which, and become damaged in frustrating ways. You're better off without one, if that's possible—and it is, if you dual-boot OS X and Linux but not Windows.
My own Mac Mini is an early bit model. Therefore, I can't speak to issues that are specific to bit Macs. I believe the instructions on this page will work for them, although you should pay attention to the caveats presented in the next section. The trouble is that Ubuntu doesn't support installing to a Mac in EFI mode, at least not as of version Some sources claim that this now works on some later versions, but I haven't tested this claim—indeed, I lack the hardware to do so!
The bit Ubuntu installation discs lack EFI support. Ubuntu has also released bit disc images for Macs. Ironically, these boot only in BIOS mode! Therefore, to rid your computer of the dangerous hybrid MBR, you'll need to jump through some hoops. An alternative to all of this is to run Ubuntu in a virtual environment, such as VirtualBox. This can be a good solution in some cases, but it doesn't give Linux direct access to the hardware and you'll lose some speed.
Enthusiasts have been working to get Windows to boot in EFI mode on Macs, with some progress and considerable pain. See this thread on MacRumors, for example. This goal appears to be more attainable with Windows 8 than with Windows 7, and success depends on your specific Mac model. I've not tested this, and the benefits are greatly reduced since you've still got the hybrid MBR on your hard disk. Thus, if you've got a Mac with an nVidia video chipset, you'll need to use the less capable fbdev drivers rather than the faster nVidia drivers.
My own first-generation Intel Mac Mini uses an Intel video chipset and is not affected by this problem, so it doesn't bother me, but it could be a deal-breaker for you. I've seen some suggestions that these problems are less serious now in April of than they were a year or two ago. I don't use such features, so I can't comment personally. Virtual terminals—I've seen reports that text-mode virtual terminals don't work from an EFI boot; however, this limitation doesn't apply to my computer.
Perhaps it interacts with the video chipset, framebuffer driver use, kernel version, or some other variable. This can reportedly limit some features, but I'm a bit unclear about the details. In my opinion, it's best to stick with bit distributions on bit hardware even on BIOS-based computers, so I don't see this as a big problem. It's possible that your preferred distribution already supports direct EFI installation, in which case the problem of installing to a Mac in EFI mode may not exist.
Check your distribution's documentation to be sure. I've tested this procedure only on my first-generation Intel-based Mac Mini. It's possible that the bit version has different requirements, or you may need to do things differently on newer bit Macs. Prerequisites Before proceeding, you'll need to download a few items: For some reason, although I was able to install Ubuntu If you have this problem, you'll have to install rEFInd before you can install Ubuntu.
Ubuntu Linux—You can obtain Ubuntu from its main Web site. The Web site describes the bit version as "recommended," but lacks such a description for the bit version. Don't worry, though; the bit version works fine for almost everything. Remember that you'll probably need the Mac-specific version to boot on a Mac if you've got a bit system.
This version can be harder to track down; I used this torrent list. I recommend using the bit version if you've got a bit EFI, as described earlier. I used a desktop version of Ubuntu I strongly recommend installing Ubuntu Burn the disc and check that it includes directories called boot, install, isolinux, and so on.
If you prefer to use a USB flash drive or similar device, you can do so. Install this package in OS X. Once you have Linux installed, you may want to install the Linux version from the Ubuntu repositories it's in a package called gdisk.
Burn the disc image like you burned the Ubuntu install disc image, or copy it to a second USB flash drive. It's part of the boot process as described on this Web page. Download either the ISO image or the binary. With these items in hand, you can proceed with installing Ubuntu, and then fix it up so that it doesn't use a hybrid MBR.
Installing Ubuntu If you've already got a working dual-boot configuration with OS X and Ubuntu, you can skip this section and jump ahead to "Fixing the Installation.
To install Ubuntu Linux If necessary, install Mac OS X. Boot into Mac OS X. Note that resizing partitions is inherently dangerous, so back up your data before beginning! The result might look like the below the Linux partition in this screen shot could as easily be blank space; I've created it here mainly to show you where Linux will reside. Open a Terminal program. In gdisk, type p to display your partition table. Verify that it's the same one shown by Disk Utility.
If you created a Linux partition, type d in gdisk to delete it. Enter its number when prompted. If you created multiple partitions for Linux with the intention of using them as you created them, you can skip this step. In gdisk, type n to create a new partition. Type p again to see the results; they should look something like this although I've got two OS X partitions: In gdisk, type w to save your changes.
When asked, type y to confirm this choice. Pick the Ubuntu install disc from the options. It may be mis-labelled as "Windows. When the appropriate screen comes up, select Install Ubuntu and proceed with a normal Ubuntu installation, except as noted in the next few steps When the Installation Type dialog box appears, select "Something Else.
Select the free space and click Add to begin adding partitions Create partitions for your Ubuntu installation in the free space near the end of the disk.
If you did this in OS X's Disk Utility, you should modify each partition by selecting it and clicking Change, then clicking the Format option and setting an appropriate filesystem and mount point. I recommend creating the following partitions: This partition is optional.
This partition is absolutely vital. Take note of the number of this partition 7 in the below screen shot. When you're done, you'll see your new partitions displayed The installation will proceed as on a PC. You can find generic installation guides online, such as this one at the Ubuntu site. When the installation finishes, the computer will reboot—straight into Mac OS X!
See the below note if it doesn't boot, though. You must now proceed with fixing it up in various ways Fixing the Installation Note: If by chance your computer won't boot, try booting the Ubuntu installer but click Try Ubuntu to run it in its live CD mode.