Choosing a Startup Volume or System

The most obvious way you can tailor the startup process to your needs is by choosing the boot volume and/or the copy of the Mac OS you want to use to boot your Mac. You can do this via System Preferences or using the keyboard at startup.

The Startup Disk System Preferences

User level:

admin

Affects:

all users

Terminal:

no

The Startup Disk pane of System Preferences is where you choose both the drive and the operating system on that drive you wish to boot into at startup. When you select this panel from within the System Preferences application, Mac OS X checks all mounted/connected volumes (including NetBoot servers) for viable operating systems—on the newest Macs, it looks for bootable versions of Mac OS X; on older Macs, it looks for both Mac OS X and Mac OS 9 System Folders. During this process you'll see the spinning "beach ball" wait cursor. When it has finished, you'll be presented with a list of all versions of the Mac OS that you can choose for your startup system (Figure 3.1). Select the OS you want to use, and either click the Restart button, close System Preferences, or switch to another preference pane. You will be asked if you want to save your change, or (if you clicked the Restart button) if you want to save the change and restart.

click to expand
Figure 3.1: The Startup Disk pane of System Preferences

You'll notice that in Figure 3.1, the volume JuniorX actually has two available operating systems to boot into: Mac OS 9.2.2 and Mac OS X version 10.2.1. This illustrates how a single volume can contain multiple valid operating systems. I could also choose to boot into Mac OS 9.2.2 from the volume Junior9. The final option, Network Startup, is visible but does not list any version of the Mac OS because none is available for network booting right now. However, even if OS X isn't currently able to find a bootable system on your network, it still lets you choose Network Startup. If you do so, the next time you restart your Mac, it will first search for a NetBoot server to start from; if it can't find one, it will revert to the OS it most recently used.

Choosing a Boot Volume at Startup

In addition to using System Preferences, you actually have three other ways to select a boot volume at startup: you can use the keyboard to access the built-in Startup Manager, to boot directly from a CD-ROM, or to bypass previously chosen settings and boot from the most recent OS X volume.

Using Startup Manager

User level:

any, unless restricted by Open Firmware

Affects:

all users

Terminal:

no

On recent-model Macs, holding down the option key at startup will bring up the Startup Manager utility. Your computer will search for all volumes that contain a bootable Mac OS (9 or X) system; the search can take a while, especially if you're connected to a network, but when it is completed, you'll be presented with a set of iconic buttons, one for each bootable volume (two are shown in Figure 3.2). If the icon for a volume has a blue "X" on it, selecting that volume will boot your Mac into OS X; selecting a volume with a blue and white Mac OS "happy face" will boot your Mac into OS 9. After you select a volume, simply click the right arrow to continue the startup process. If you need to rescan for volumes (e.g., if you've subsequently attached an external hard drive, or connected to a network), click the circular arrow.

click to expand
Figure 3.2: The Startup Manager utility

Tip 

If you use the Startup Manager utility to choose a boot volume, you'll notice that it often takes a long time before you can actually select a volume and click the continue button. This is because your Mac is searching for any connected network volumes that could be used to boot your Mac. You can stop this search by holding down the mouse button until you see the spinning cursor stop.

Tip 

If you need to eject the CD/DVD drive from Startup Manager, press command+. (period); if you then insert a CD with a bootable OS that you want to select as your boot OS, be sure to click the rescan button to cause it to show up as an option.

I emphasize the term volume in the previous paragraph because unlike the Startup Disk pane of System Preferences, which allows you to select from multiple bootable operating systems on each volume, the Startup Manager utility only shows a single OS per volume—the one most recently used to boot up your Mac. In other words, if you have a volume that contains Mac OS X and Mac OS 9, and you most recently used that volume to boot into OS X, that volume will only show up once on the Startup Manager screen, and will only be selectable as a Mac OS X boot volume. You can see this difference by comparing Figure 3.2 (Startup Manager) with Figure 3.1 (Startup Disk in System Preferences); the same computer was used in both examples. The volume JuniorX has two bootable systems, Mac OS X and Mac OS 9, but whereas both are selectable in Figure 3.1, only OS X is an option in Figure 3.2. Note that the term volume means any hard drive, removable disk, or partition. (See Appendix B for more info on volumes and partitions.)

Note 

Macs that can take advantage of the Startup Manager include all iBooks; PowerMac G4 models with AGP graphics slots (including the G4 Cube); PowerBooks with FireWire ports; iMacs with slot-loading CD drives; and any Macs produced after these models. On earlier Macs, the option key does not invoke Startup Manager.

One other difference between using Startup Manager and System Preferences is that the volume you choose in Startup Manager is only used as the boot volume for that particular startup. The next time you restart/start up, the volume/system chosen in Startup Disk preferences will be used. In other words, Startup Disk settings in System Preferences remain until you change them; selections made in Startup Manager only affect the current startup.

Booting from a CD or DVD

User level:

any, unless restricted by Open Firmware

Affects:

all users

Terminal:

no

There are times when you may want to boot from a CD or DVD that contains a bootable OS (a Mac OS installation CD, a disk utility CD, etc.). If your Mac is already up and running, you can simply insert the disc and use the Startup Disk pane of System Preferences to select it. However, if your Mac isn't running or if it won't start up because of some kind of problem (or if you just don't want to use System Preferences and make the CD selection "permanent"), you can force it to boot directly from the CD/DVD. Simply place the CD/DVD in the drive, and hold the C key down at startup. If you need to eject the drive to insert the CD, hold down the eject key on your keyboard (F12 on non-Apple keyboards), or the mouse button, until the drive opens.

When OS X and OS 9 Are Installed Together

User level:

any, unless restricted by Open Firmware

Affects:

all users

Terminal:

no

If you have a single volume with both Mac OS X and Mac OS 9 (the default installation on new Macs), and your Mac is one that can boot into OS 9, there's one other trick you can use, but it's a very specific trick that only works in one specific circumstance. If you last booted into OS 9 and you want to instead boot into OS X, you can hold the X key down at startup; this boots you into OS X and changes the Startup Disk preferences to Mac OS X, making the change "permanent." You can't press the 9 key to do the opposite, and it doesn't let you change boot volumes; it doesn't do anything else at all. But if you need to boot into X in these particular circumstances, it's a handy tool.

As you read the different options for choosing a startup system, you may have noticed that if you only have a single volume, and have both OS X and OS 9 installed on it (or two copies of OS X or OS 9), it's a bit tricky to switch between the two without starting up your Mac, and then using System Preferences to switch. This situation is one where partitioning your hard drive comes in handy, as each partition is considered a different volume, allowing you to install a different OS on each. I'll talk more about partitioning in Appendix B.

Once you've chosen a startup volume/system, the computer begins booting into that OS and the boot panel appears. Here's how to make it appear the way you want it to.




Mac OS X Power Tools
Mac OS X Power Tools
ISBN: 0782141927
EAN: 2147483647
Year: 2005
Pages: 152
Authors: Dan Frakes

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