A convenient way to back up an OS X machine


Wiebe-tech's FireWire-to-IDE converter and Carbon Copy Cloner together make a great way to back up an OS X machine

When I advise people about how to do backups for workstations and small servers, I generally tell them that they should keep their data in as few places as possible and back those places up to some sort of disk. On a Linux machine, you might back up a few files in /etc and all of /home and /usr/local. On an average Windows box, backing up My Documents ought to be sufficient. That's not a perfect technique, but I think that it's generally the best approach.

Happily, it turns out that things are even simpler and better under OS X.

A while ago, Dan over at Dan's Data (a great site for hardware and gadget reviews) reviewed a FireWire-to-IDE converter from WiebeTech. You plug it into a commodity IDE hard drive and you have a hard drive with a FireWire connector. Of course, you can buy FireWire hard drives in lots of places. They're the same thing: an IDE hard drive and a FireWire converter, just inside an enclosure. There's no price advantage to buying the components separately if you only buy one hard disk. But you really want more than one backup, and you can plug a different drive into the converter whenever you like (though you want to be a little careful not to bend a pin). So what the converter really amounts to is a removable-media drive where the media are cheap IDE drives. Like Iomega's old Jaz drives, the "platters" cost around US$100 but instead of holding a gig or two, they hold about 100 GB as of this writing and they're getting bigger all the time.

That's a great backup medium if you ask me. But how to do the backup? Enter Carbon Copy Cloner. CCC will create a bootable file-by-file image of your OS X disk on another disk. It will even back up your boot disk. (There's nothing to prevent CCC from backing up inconsistent data if one of your programs is writing furiously to the disk as it's being backed up, but as long as you're backing up a pretty quiet machine I think the risk is minimal.) CCC is a shell script wrapped with a GUI interface. For my purposes, running it with a GUI isn't any better than running it in a terminal window would be, but it's certainly no worse for me and it's no doubt much better for lots of other folks.

CCC can actually work in either of two ways. As it's shipped, it insists on doing a complete copy every time, but if you go to its preferences and click a few times you can have it download and install a Perl module and a Perl program that uses the module which CCC can then use to copy only modified files. The Perl module has the additional advantage that it can copy a few things that the plain shell commands can't.

Once you've made a backup, you can prove to yourself you have an identical bootable backup by leaving the FireWire disk plugged in and rebooting with the option key down. Your Mac will give you a choice of disks to boot from and you can choose the backup drive.

Separately, those products are very good. Together, I think they're great.

Posted: Mon - November 17, 2003 at 11:09   Main   Category: 

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