One question I don’t get asked very often is, “How do I safely back up my data?” You know you need to do it, but like doing your taxes, you’re putting it off until the last minute. Unfortunately, with a disk failure you don’t exactly know when the last minute is. In this post, I’ll boil it all down so you can quickly understand the issues and tell you how I back up my digital files and why I do it the way I do.
There are three possible situations you may need to recover from that require you to back up the data on your computer:
1. Disk Failure
You can lose data on a disk when the disk stops physically working for some reason.
2. Disk Corruption
This is the more common but often overlooked way a disk can fail. I’ve seen this happen to a photographer shooting tethered (directly connected to the computer) when the cable became disconnected from the camera while writing the file to disk. The result was a corrupted directory tree (that’s the file that keeps track of the physical location of all files on the disk). His files started spontaneously disappearing off the disk, which as you might imagine, caused him a fair amount of distress.
3. Physical Loss
A fire that destroys your office, home etc., theft of your equipment, you get the idea.
The simplest way to back up is to burn crucial files to a CD or DVD, or better to write it to a thumb drive. The drawback of this method is that if a loss does occur you have to find a computer running the software you need, and even if you can get your work done, you’ll need to get your system fixed/replaced, and then spend the better part of a day re-loading and re-configuring software. Don’t discount the amount of time and aggravation (and loss of business) this will cause you.
A better way to back up is to make a complete bootable backup to an external firewire hard drive. The benefit of this is that if your disk fails, you can connect the external drive, start up holding the option key, choose to boot from your backup drive and your will be right back where you were on your last backup within minutes. Minutes! Not hours or days. If your computer fails altogether, take your backup drive to another mac you have access to and boot up with it (keep in mind it needs to run the same processor that your machine had: Intel or PPC) and you will be looking at your system, just the way you like it, but on another machine.
The bootable backup method has a huge advantage in that it let’s you keep working if you are on a tight deadline, rather than shifting gears and spending the rest of the day looking for someone who has a computer that will open your files.
My solution: Shirt Pocket’s SuperDuper! ($30). Allows you to make a BOOTABLE backup on an external drive. After the initial backup, use it’s ‘Smart Update’ feature to just update the changes you made to your system since the last backup, which is much faster. It’s easy and non-technical and you can even schedule regular backups so it will do them automatically. You can even use SuperDuper! to clone your backup drive back to your computer’s internal drive if a software update screws up your system. [I am not in any way affiliated with the company that makes SuperDuper!, just a big fan of things that make my life easier.]
A Step Further: If you have a drive big enough to hold 2 complete backups, use Disk Utility to partition it into 2 equal partitions (it will appear as two separate disks in the finder) and alternate backing up from one to the other. This gives you two levels of undo should you discover a problem with your system. Of course you could use two separate externals to do this too.
Why don’t I use Time Machine? Time Machine is great when you have lots of small files that change frequently and you only need to retrieve a file or two at a time. I can still do this with my alternating 2 drive backup (though it’s lacks a pretty interface) but a bootable backup also protects me against a catastrophic disk failure and lost work time while Time Machine does not. I also tend to work on large image files which can fill up a Time Machine drive pretty quickly.
Files already on an external drive: If you store files solely on an external drive like I do with my images, you’ll need a backup of that too. I use an identical external drive and SuperDuper! to periodically keep it in sync. Why not use a RAID array ? I have 2 problems with RAID. First, non-technical users don’t always understand that in some configurations RAID arrays provide no redundancy at all. Second, as mentioned before if a write error corrupts the directory tree, a RAID array that does provide redundancy will automatically propagate that error to the backup drive, causing the backup to fail as well. The same would be the case with maliciously crafted code. Manually updating your backup gives you another layer of safety.
I currently use the Lacie 2Big Triple, a drive housing with 2 separate removable drives inside. It can be configured as a RAID array, but I set it up as two separate drives. The triple interface (Firewire 800, FW400, USB2) insures I can connect to whatever I might need to and the single housing means the 2 drives share a power adaptor and cord, cutting down on the mess under my desk. Lacie uses reliable brand-name disks inside as well, Seagate in my case. The Drobo storage system has become popular with some high visibility photogs, but I have some serious reservations about it, and the 2Big Triple comes in at about half the price for the same amount of storage.
While having two copies protects against disk failure and disk corruption, remember that if you suffer a physical loss like fire or theft and both copies were in the same place, you’ll be up a creek without a paddle. To insulate yourself from this issue, you’ll need a third backup in a separate location. I know you’ll never do it, but don’t say I didn’t warn you!