One of the things I loved about the old Mac OS Classic was that to create a bootable disk, all you had to do was make a folder named System Folder, drag in System and Finder files and an Appearance Folder, then drag your bare-bones System Folder to a disk — hard drive, Zip, floppy, CD-R, etc — and voila! you were in business. Usually one would add a few more items like Control Panels and Extensions folders, Preferences and Fonts folders, but it was a simple, quick and not-too-dirty way to make bootable disks.
Alas, you can’t do that with OS X and its thousands of tiny, usually invisible files, but the next best thing is disk cloning, which is to make a copy of an existing bootable volume on another disk or drive. This is excellent for backups, but has the added advantage of allowing you to create bootable disks without going through the hassle of running an OS X installer program.
There are several software utilities available that can clone drives, but it’s hard to go wrong with Mike Bombich’s Carbon Copy Cloner, which is offered as uncrippled shareware, with donations suggested if you like the software and decide to continue using it once you’ve checked it out.
Besides drive cloning, Carbon Copy Cloner allows you to do backups and drive synchronization. supporting any HFS+ formatted partition or hard drive (excluding volumes used for Time Machine) as well as FireWire and USB hard drives, including iPods. Note that not all FireWire hard drives are bootable with Mac OS X, and while it is sometimes possible for Intel-based Macs to boot from USB hard drives, it’s not a sure thing.
Note also that for bootability you must format the FireWire drive with the appropriate partition map using Apple’s Disk Utility or other formatting software. The Disk Utility formatting selection sheet (Options button) is self-explanatory.
You can read more about formatting issues and my using CCC to create a bootable clone of my main hard drive to a SimpleTech Duo Pro Hard Drive here.
CCC’s marquee function is cloning one hard drive volume to another, copying every single file to create an exact replica of your source hard drive. Aside from the obvious comprehensive backup you get, if it’s done to a bootable volume you can, say, send your computer in for repairs while continuing to boot and use your standard work configuration until you get your computer back, then just clone the FireWire drive’s updated content back to your internal drive.
Using CCC for Backup and Synchronization
CCC can also be used as a backup utility. When you select a source volume, CCC displays the contents of that volume (including normally hidden items). Uncheck items that you don’t want to back up, select a target volume, and press the clone button. CCC also is smart enough to scan the source and target volumes for files to be copied, and only copy only files that have changed. You can also schedule automated backups.
Another advantage of CCC backups is that rather than using proprietary archival methods, CCC backs up your data to an ordinary filesystem that you can browse in the Finder. To restore your backup data, just select your backup medium as the source drive and the backup destination as your new target volume, and let CCC do its stuff.
Carbon Copy Cloner 3 also supports cloning to disk images, which you can use to restore content to a physical hard drive and produce a bootable, exact clone of the original.
Carbon Copy Cloner 3 requires Mac OS X 10.4.8 or later. Version 2.3 is still available for Mac OS 10.2 and 10.3 users.