Face it. Death is a part of life. This is true of people. It’s true for hard drives,too. Those containers of mass data on high speed spinning disks have a life span just like we do. So how long will a hard drive last? Great question!
The MTBF is touted as a feature in the specifications of most hard drive. What is it? MTBF stands for Mean Time Between Failures. Mean means average. So the MTBF of a drive is the average number of hours it will work before it fails. The operating word here is average. Since it is an average, some drive will fail before the MTBF and some will last longer. In other words, you just don’t know when the drive will fail. You do know that it will fail.
Most photographers I know use the JBOD method of storing their work. JBOD is the acronym for this. It means Just a Bunch Of Drives. This is a risky form of storage because unless there are copies of each of the drives, data will be lost when a drive fails. Some photographers and a lot of videographers use JBOD by copying work to disks then putting them on a shelf. According to one of my sources a hard drive stored this way has a 25% chance of never spinning up again after a year. At the very least store bare naked hard drives in static free bags with a packet of silica gel to protect against static damage while handling and the “drive killer” humidity.
A lot of photographers I have spoken with trust their data on individual hard drives and even have backups of them stored on a shelf somewhere. They tell themselves that their data is safe. This is a rational lie.
It isn’t safe.
There are lots of reasons why this isn’t a good strategy.
- The backups have to be updated every time a file is changed.
- No one knows how long a drive can sit idle before it freezes
- Drives sitting around can get lost
- One out of four drives stored without being spun up regularly will fail
- It’s too much work to keep up with the updates
Redundant Array of Individual (or Inexpensive) Drives offer a reasonably robust solution. There are some things you want, OK, need to know. There are several flavors of RAID. The most common are RAID 0, RAID 1 & RAID 5.
- RAID 0 stripes the data across multiple drives. It’s very fast. If one drive fails all of the data is lost.
- RAID 1 mirrors the data on one drive onto another. This is very safe. It’s also much slower and more expensive. It requires two drive to store the data of one drive.
- RAID 5 distribute the data across multiple drives using parity so that any one drive can fail. After the failed drive is replaced the remaining drives remap the data. Typically RAID 5 uses four identically sized drives to store the data that would be held on three drives.
Several years ago Data Robotics introduced Drobo. These RAID 5 like systems don’t need the drives to be the same size. Lower terabyte drives can be replaced with larger ones without data loss. The Drobo and its accompanying software Drobo Dashboard monitor the health of individual drives and warn when a failure is imminent or when a drive is approaching its capacity.
Drobo’s BeyondRAID technology provides two critical improvements over RAID 5. First traditional RAIDs require all of the installed hard drives be the same capacity. Drobos can use multiple drive sizes. As a matter of fact when a Drobo is running short on space, one of its existing drives can be replaced with a larger one. Best of all, and the second improvement is that BeyondRAID only has to remap the data stored on the replaced drive to the new one saving lots of time. Traditional RAIDs must rebuild the entire volume. This can take days.
While true of hard drives, our data doesn’t have to end. A good backup strategy that includes three complete copies of your data along with technology like RAID 5 and Drobo’s BeyondRAID will keep it safe for, well, a lifetime. Maybe even longer…
Kevin is a commercial photographer from Atlanta. He works for fashion, architectural, manufacturing and corporate clients. When he’s not shooting, he contributes to Photoshop User magazine & writes for Photofocus.com.