Yes, You Need to Backup

Sorry. I know no one wants to think about this dirty subject, much less talk about it. But is is a necessary part of a digital artist’s process.

Back in the “good old days” images were created on film. You kept the film in holders or sleeves in a file of some sort. Barring major fire or flood, you were pretty well backed up. The negatives or slides were fairly insensitive to water, tolerated a wide storage temperature range, and would last for decades or longer.

Forward to today. It has been many years since I exposed a piece of film. ALL my work is digital. And all the derivative works I create are digital. There are significant advantaged to digital images, but there is one glaring, horrible downside: when the disk they are on dies, they are gone. They are not a physical object.

Oh, but disks are very reliable. You can’t remember the last time one of yours crashed. (Cue whistling in the graveyard music). Here’s the reality: your disk is about to fail and there is little ability to predict when. After it fails is not the time to be doing a backup.

In a past life I was an engineer, so I know something about this technology. I’ll try to keep it pretty basic. Most of us use rotating magnetic storage (e.g., the hard disk). This is an amazing technology. Bits are stored as microscopically small magnetic blobs on platters of metal spinning at, typically, 5400 or 7200 RPM. The data is read and written by “flying heads” that fly above the surface of the platter a few micro inches away. This is like a fighter jet flying at supersonic speed 10 feet off the ground. It’s a wonder it works, but it has been engineered with enough layers of protection to make it very reliable. The other fast growing technology is Solid State Disk (SSD). It is completely different and usually much faster. Just because it is smaller and faster does not make it more reliable. There are many more failure modes associated with SSD than rotating disks.

What does this matter to me? My disk drive is rated at 1,000,000 hours MTBF (mean time before failure). It should be good practically forever. There is a reason disk makers throw out numbers like that. They are very impressive without really meaning much. It is a statistical measure of a large population of devices. It does not mean yours or mine won’t fail tomorrow.

What to do? The ugly “backup” word. I won’t recommend specific software or hardware, except to say if you are using Macs, please turn on Time Machine immediately. Instead I will give you an idea of the paranoid extremes I go to.

Yes, I use Time Machine for one level. It is a marvelous invention. It backs up my images and the computer every hour. My images are actually stored on a RAID drive. This means the information is redundant and one drive can fail with no loss of data. My drive is also very fast. The data on this RAID disk is also backed up daily to 2 other RAID drives. All of this is completely automated and requires no attention from me. About once a week I rotate a copy of my image data to off site storage, so it is backed up in another physical location.

I’ll confess it again: I am paranoid about this. But the last 2 times my computers crashed I didn’t lose anything. I use (and love) SSD as my main computer storage. I have stacks of rotating disks with many terabytes of data on them. With a good backup plan I don’t worry at all about losing data.