However, don't expect to use the Finder's Burn Disc command (in the File menu) to accomplish this feat.
If all you want is to make an exact copy of a bootable disc (such as the Mac OS X Install disc) for use as an emergency disk, it's relatively easy to do. You can certainly create an exact copy of a bootable CD or DVD that will also be bootable, but making a useful customized bootable disc is not as simple. So, if you own a CD or DVD burner (Apple's SuperDrive will make things go most smoothly), can you create one of these bootable discs yourself? Yes, with some limitations. Bootable CD or DVDįor troubleshooters, by far the most useful and commonly used bootable disc is a bootable CD or DVD.
Especially convenient when traveling are small, portable FireWire drives. One weakness of this approach is that if the entire hard drive fails, you will not be able to start up from any partition.Ī better alternative is an external hard drive. You could then use the second Mac OS X installation as your emergency partition. If you've divided your internal hard drive into several partitions, the simplest way to create an emergency startup volume would be to use a Mac OS X Install CD to install Mac OS X on more than one partition. In fact, given that Zip discs max out at 250 MB, and a typical Mac OS X system can require more than 600 MB, it's unlikely that you'll be able to use a Zip disk as a Mac OS X startup disc under any circumstances. Thus, you cannot simply copy a Mac OS X System folder to a Zip disk, for example, and expect it to function as a startup volume. And there is the potential issue of setting up a default user account. In addition, numerous invisible files, mostly related to the underlying Unix OS, need to be copied as well. The primary reason is that the essential System files are not all in the Mac OS X System directory. Even Mac OS X's Disk Utility can burn a bootable Mac OS 9 CD if you first create a disk image of a bootable CD for it to copy.Ĭreating a custom bootable Mac OS X volume presents considerably more difficulties.
CDs, however, presented a special problem: A CD needed some special boot code for the Mac to recognize the disc as a startup volume at a point in the startup process when it typically would not yet have loaded the code needed to recognize CDs in the first place! This problem was solved by utilities such as Roxio's Toast, which created a bootable CD with the needed special code from any original that contained a System Folder. This method worked with hard drives as well as most removable media (such as Zip disks).
Of special interest are the procedures for making a custom bootable CD.Ĭreating a bootable volume in Mac OS 9 was about as simple as it could possibly be: You just dragged a copy of a System Folder to the volume, and (assuming the software was recent enough to run on the Mac in question) you were able to start up your Mac from that drive.
In this section, I discuss how to set up an emergency volume using several different media. More recently, that emergency volume could have been a portable FireWire hard drive.
In past years, emergency bootable volumes took the form of floppy disks or (more recently) CD-Rs or Zip disks. (In addition, as new models of Macs are released, it often takes time before an updated version of a third-party utility's CD, modified to start up the latest Macs, is released.) In any case, it's convenient to be able to create your own custom bootable emergency disk-one that contains all the software of your choosing. Still, these discs may prove less useful as updated versions of the software are released, for which you do not have a CD. Third-party repair utilities also typically come on their own bootable CDs. At these times, a bootable emergency disk becomes an essential tool for repairing the problem drive, or at least recovering data from it.īecause the Mac OS Install disc is bootable and provides access to Disk Utility, you can use it as an emergency boot disc. They become especially valuable if the data on your default drive gets corrupted in such a way that your computer cannot start up from the disk. Alternative startup disks can be convenient when you're doing something that cannot be done to the current startup drive (such as disk repairs with some utilities). Troubleshooters often find it useful to have a startup disk other than the one that's normally used-typically, the Mac's internal drive. Learn More Buy Creating an Emergency Startup Volume