Installing Linux on an Apple iMac

What This Document Does

This document provides supplemental and background information on how-to install a Linux distribution on an Apple iMac computer.

Almost every time I install an operating system on a computer I know that I will do it differently the next time. Hopefully these instructions will provide you with enough background information to help you make the best choices during the installation so that when the installation is complete, you have an installation that you can configure to meet your requirements. By combining the information in this how-to with the instructions that accompany the Linux distribution that you are using, you should be able to complete the installation without that nagging doubt that you could do it better next time.

This document does not replace specific step-by-step instructions that accompany a Linux distribution. Specific instructions will differ depending upon the iMac model you have, the distribution of Linux that you select, and the reason why you are installing Linux in the first place.

Where instructions are included they address either short-comings in the instructions that I have seen, or they provide instructions for specific points in the instructions where I was confused when I tried to follow the instructions.

Disclaimers

Every attempt has been made to be accurate and complete, but due to the differences in systems and distrubtions there is no guarantee that following these instructions will work. For that reason, backup your system, and make note of your iMac's configuration parameters before changing anything so that in the worst case scenario, you can restore your system.

This document has links to Web sites for supplemental information. I have tested these links, and they worked at the time this document was created. But the Web sites are beyond my control; therefore by the time you read this some of the links will undoubtably be broken. You should be able to find a new link to the document by searching for the document title from a search engine such as .

Thinking about the following issues before you start will make for a smoother installation.

What Do You Want To Do?

There are a variety of reasons why you might want to install Linux on an iMac, including:

• You want to learn Linux.
• There are applications available for Linux that you want to use.
• You've heard that software runs faster on the iMac under Linux than the Apple Macintosh operating system (OS).

Having a clear idea of what you want to accomplish may help you make better choices for your requirements during the process of installing and configuring Linux.

Which iMac Computer Do You Have?

Another detail that you need to know before you start is which iMac you have. The reason that you need to know this is that it effects how you will get your iMac to boot Linux, or how you will configure the iMac to support dual booting either Linux or the Apple Mac OS.

I have one of earlier iMacs, and when reading the there were references to "New" or and "Old World" ROM and in the Yellow Dog Linux Guide to Installation (included in PDF format with the distribution) there are references to "iMacs older than Rev A."

So how do you tell if you have "New-" or "Old-" ROM and which "Rev" your iMac is?

All iMacs are New World ROM-based (the iMac computer was the first New World ROM-based computer from Apple).

Again, the main reason you need to know this is for determining the best way to boot your iMac with Linux. So how can you tell which iMac you have? The has several articles containing the necessary information. You might want to read the following articles:

Help please: If you know of other documents that offer information on other iMac models (particularly the newer ones), or how-to tell one model from another please send a pointer to the document and I will add it to the list. The goal is to build a table here of every iMac model with information to help people identify their system.

What Do You Want To Do With Linux?

You need to decide what you want to do with the iMac once you install Linux. For example, do you want to run only Linux, or do you wish to run Linux sometimes and the Apple Mac OS other times? Again, the answer to this question will effect the choices you make during installation.

Which Peripherals Do You Want To Use With Linux?

Of all the accessories that come with the iMac, the Apple mouse is the cheesiet piece of hardware that I have ever used (pun intended). As a consequence, I bought a Microsoft optical IntelliMouse that I normally use on the iMac. When I wanted to install Linux on the iMac, I did not want to deal with anything that might complicate the process, therefore, I put the original Apple mouse back on the system.

The correct way to address this issue is to actually check the distributions to see which mice, and for that matter, which hardware they support. Picking a distribution with the most support for the hardware you want to use will make it easier to install and configure Linux.

Mice and keyboards are probably not too big an issue, for the most part they come with the iMac. More problematic will be devices such as USB (or on the later iMacs Firewire) connected external drives (Floppy, CD, DVD), printers, scanners and digital cameras.

You should make a list of the manufacturer and model number for all the peripherals you want to use with Linux before you start looking for the distribution that will met your requirements.

Which Applications Do You Want To Use With Linux?

You need to think about what applications you want to run, not so much because it may be hard to find an application, but rather, the applications may effect how you choose to layout your Linux partitions and how large you make them.

For example, I wanted to run typical desktop software like , and I would like to be able to import photos from my digital camera, crop, size and fix them up, and then either print them or burn a CD-ROM of them. Therefore, spending some time looking for the applications you want to run, finding out what the application needs (disk space, libraries, shell, graphic user interface) so that you know how best to layout your Linux partitions and which software packages you want to select during installation.

Available Distributions

The following organizations provide Linux distributions for the iMac (PowerPC):

Note: The above list is in alphabetic order. The list implies neither a ranking nor an endorsement.

Help please: If you know of another distribution please send a pointer and I will add it to the list.

Getting a Distribution

Ordering a Distribution

While you can download a distribution you may want to consider ordering CDs from a distributor. The advantages of ordering a distribution is that you get a CD (versus spending the time to successfully download the image and burn a CD), and you will get support for any installation issues you encounter (versus looking for answers in the newsgroups and on the Internet). You can order a distribution from most of the distributors listed in the Available Distribution section above.

Downloading a Distribution

It is possible to download a distribution, typically from an FTP site. The best way to find the FTP site is to start at the Web sites listed in the Available Distributions section of this document, and from there you can find a link to either the distributor's FTP site or a mirror-site.

A couple of things before you start the download:

• Unless you have a high-speed link, downloading is going to take considerable time.
• Get a FTP utility program (versus trying to download this in a browser). You may want to consider an FTP utility that supports restarting the download if there is a problem before the entire download is complete.
• Be patient. Lots of people are trying to do a download, so be prepared for messages such as the site is busy. You will have to keep trying until you can make a connection and perform the download.

The following links should connect to the downloadable distributions:

Note: Again, the above list is in alphabetic order. The list implies neither a ranking nor an endorsement.

Burning a CD

Installing an operating system across a network or between two machines may be feasible, but I think it is better to have media such as a CD. Therefore, look for a distribution that allows you to either download or create a bootable CD-ROM image. You will need to have a CD-ROM burner and software that will let you work with a CD image.

Preparing the iMac

Getting Your iMac's System Details

Before you start, you should know some details about your system if for no other reason than they may be useful if you decide you want to put your iMac back the way it was. The easiest way to do this is to run the Apple System Profiler. To do this:

1. Click the Apple menu.
2. Click the Apple System Profiler.

The Apple System Profiler dialog box displays a row of tabs labeled System Profile, Devices and Volumes, Control Panels, Extensions, Applications, and System Folders. If you scroll down through the report you will see more detailed information including information about the ROM and the hardware devices such as hardware connected to the USB ports, the disk controller and video system. You can select any tab to see the related details, but even better, you can print this information out. To do this:

1. Click on File (the File menu).
2. Click on New Report... The New Report dialog box will open. Select the check boxes (so that a check-mark appears) next to the details that you want to include in the report. I would suggest that you select all the options even if it may take a while for utility to build the report.
3. Click on the OK button. An Apple System Profile (ASP) report with the current date will appear in a new window.
4. Click on File.
5. Click on Print 'ASP report [date]'

This report provides a lot of useful information, including a software, memory, hardware, and network overview.

Note: It is actually a good idea to print out a copy of this report from time-to-time and keep it handy so that if you have a problem and need to contact a vendor for support you have this data.

Backing up Your Data

However you decide to install Linux on your iMac it is highly likely that you will destroy the data which is already stored on your hard drive. This is especially true if you need to change the way the hard drive is set-up or partitioned, and even if you have utility software that claims it can "re-partition" a drive on the fly, you wouldn't want to use it until you had done a back-up. So do a back-up now.

Every one has their own favorite way of backing up a computer. Here is what I do:

• I only backup my data. About once a year I reinstall the OS and applications just to clean the system up, so my philosophy is not to back up anything that can be just as easily reinstall.
• I keep all of my data in a single folder (actually there is a main folder, and then a series of sub-folders. Therefore, if I have a copy of that folder somewhere, for all intents and purposes I have a back-up.
• I hate tape systems and back-up software. Lots of times I have run the back-up and the software says everything worked fine, and then when you go to restore the data you can't. So instead I burn a CD-ROM of the data I want. It is a great snap-shot of my data at a point in time and I can restore it by dragging and dropping the folders from the CD to the location on the iMac where I want them.

Note: There is a down-side to this approach. The configuration data, for example the phone number for my Internet Service Provider (ISP) is embedded in program files that I do not keep in my data folder. Therefore any application configuraton data that is stored in the Apple System Folder or in application folders can be lost if you back-up the same way I do. You need to write down that configuration information somewhere.

Checking That You Can Restore Your Data

Seriously, the next couple of steps fool with the structure of your hard disk, and it can mean that the data currently on your hard disk will no longer be accessible. So, check to make sure that your back-up is good by making sure you can restore files from the back-up.

Booting the Mac OS Distribution CD

To change the drive configuration or parameters, you have to have booted the iMac from a different drive than the one you are going to change. Typically this means you have to boot the iMac from the CD-ROM containing the version of the Apple Mac OS that came with your system. To do this:

1. Put the Apple Mac OS CD in the CD-ROM Drive.
2. Click on the Special menu.
3. Click on Restart.
4. Hold down the letter C key while the iMac restarts. When you see the smiling Mac on the screen, then the iMac is starting from the Apple Macintosh CD. When it has booted from the CD the desktop background should have a repeating image of a CD with the letters "CD" behind it.

Note: You may see an informational message that "Complete functionality of USB devices is not available when started up from this installer CD." You can close this message box.

Partitioning the iMac Hard Drive

Note: The instructions in this section are based on Mac OS 9.

Again, my only experience is based on the Yellow Dog distribution. In their they make reference to using multiple disks, one for the Apple OS and one for Linux. I assume this recommendation is due to the fact that their distribution targets PowerPC-based systems (of which the iMac is merely an instance).

In the case of the iMac, this dual disk approach makes no sense to me, because my iMac only has a single (internal) disk and I couldn't see using a USB connected disk for an operating system installation.

Based on the information I got from the Apple System Profiler for my iMac I could tell that even with the Apple Mac OS version 9.04, the applications I run, and all my data, I didn't use more than half of the available disk storage. Therefore the best approach for me at this point was to repartition the hard drive in my iMac with half of the drive (2GB) for the Apple Mac OS, and half (2GB) of storage for Linux. Again, you need to start or boot your iMac with the Apple Mac OS. Once you have booted your iMac from the Apple Mac OS distribution CD:

1. Double-click on the Utilities folder to open it.
2. Double-click on Drive Setup icon to start the Drive Setup utility. A Drive Setup dialog box will open.
3. In the List of Drives list box click on the volume name of your iMac's hard drive. The hard drive in an iMac usually lists first, it is the ATA drive and usually is Bus 0, ID 0, and LUN 0. The second drive (the ATAPI) is likely the CD-ROM drive that you just booted from. When you select a drive, the Initalize... button will become active (it will no longer be greyed out).
4. Click on the Initialize... button. An Initialize dialog box will open, and you will see a warning message that "Initializing will destroy all data on the following volumes:" and in the list box, you will see a list of the current volumes.
5. Click on the Custom Setup... button. A Custom Setup dialog box will open.
6. In the Custom Setup dialog box, select 1 Partition from the Partioning Scheme: drop-down list. In the Volumes frame, you will see one box, (representing the partition) labelled "untitled".
7. In the Volume info frame, type in aproximately 2055 as the size in megabytes (MB). The illustration of the partitions in the Volume from will now show an "untitled" partition and "Extra" space. This means that you are going to create one partition of 2GB for the Apple Mac OS, and the other 2GB will be empty or unallocated until you partion it for Linux during the Linux installation. Make sure the Type: in the Volume info frame says Mac OS Extended.
8. You are about to make a decision that you cannot undo, short of reinstalling the Mac OS and restoring your data from your last good back-up, so when you are positive that this is how you want to proceed, click the OK button.
9. You will return to the Initialize dialog box. Now click on the Initialize button.
10. A warning dialog box will appear saying, "The selected disk can be used as the startup disk only for PowerPC computers." Click on the Initialize button.
11. In the drive setup dialog box, you will see some progress messages, and then (hopefully) a message saying, "Initialization was successful." In the List of Drives list box you will see the volume "untitled".
12. Click on the File menu.
13. Click on Quit.
14. Click on the Close button to close the Utilities window.

Reinstalling the Apple Mac OS

After you have created the one partition that uses approximately half of the space on your iMac's hard drive, you can reinstall the Apple Mac OS into this partition. There is nothing too tricky to this, and there are likely instructions that either came with your iMac or in a book such as O'Reilly's "Mac OS in a Nutshell".

Restoring Your Data

When you restart your iMac after reinstalling the operating system, you can use the Mac OS Setup Assistant to reconfigure your iMac, and then you can restore the applications and data that you want to have on your iMac.