Digital Storage for Photographers - RAID 1 Storage Solutions
Digital photography has forced professionals to rethink archiving of work. Physical negatives have transformed into digital files, which are only as stable as the media on which they are stored.
Hard disks are extremely delicate pieces of technology: a magnetic storage disc read by a mechanism that under normal circumstances never physically comes in contact with the platter. Problems arise when conditions are not normal; if the reading mechanism touches the platter… well, kiss the data goodbye. Computer hard disks are more reliable than they were a decade ago, but disk failure is still a fact of life.
So, it's not a matter of if a hard disk will fail; it's a matter of when a disk will fail. Armed with this knowledge, it's imperative that photographers implement a solid backup scheme for digital images. This article is going to cover one way of protecting data – RAID 1 storage.
If there is one thing that computer geeks like, it's acronyms. RAID stands for “Redundant Array of Independent Disks.” There are many different types of RAIDs, but for the purposes of this discussion we're going to look only at RAID 1.
RAID 1 is the simplest form of RAID. It requires two disks of equal size to function. Data is mirrored to both drives in real time. If one of the two disks crashes, no data will be lost. The flip side to this is that a 2TB array when configured as RAID 1 will only net 1TB of usable space.
Most drives that support RAID 1 will also support RAID 0. This type of RAID offers no data protection. Instead, it writes data simultaneously to both physical disks. This results in an increase in read and write performance, but sacrifices any type of data protection.
If one of the disks of a RAID 0 crashes, all data is lost. Since most RAID systems will be configured as RAID 0 out of the box, make sure to refer to the documentation in order to change the array to a RAID 1. This is generally done via a physical switch or via an included software application.
Before you start feeling bad about that 2TB being sliced in half by your RAID 1 configuration, think about what you net from this security.
If your digital camera produces RAW files that are about 20MB each in size, that 1TB will hold about 50,000 pictures. This should be ample space for working professionals and enthusiasts alike.
What to Look For in an Array
Shopping for hard drives can be daunting. There are dozens of manufacturers churning out what is, essentially, a utilitarian item. Pros looking at RAID 1 systems should be sure to get one that features FireWire or eSATA, as they offer higher performance than the ubiquitous USB 2.0 interface.
Taking a look at the Western Digital My Book Studio Edition II might be a good place to start. The external drive, available in 1TB and 2TB capacities, sports a quad interface: USB 2.0, FireWire-400, FireWire-800, and eSATA. It can be configured as a RAID 0 or RAID 1, and comes preformatted with the HFS+ Macintosh file system. Windows users will need to reformat the drive for use in that operating system.
The My Book comes preconfigured as a RAID 0 array. A software application is included to set the drive up as RAID 1. The system is user-serviceable; you won't even need a screwdriver to open the case. You are limited to using Western Digital's GreenPower hard drives for disk replacement and upgrades. These disks use less power than standard hard disks, but don't offer the same level of performance.
LaCie makes a RAID 1 system as well: the 2big . It's available in two versions: the Triple Interface edition features USB 2.0, FireWire-400, and FireWire-800, while the Dual Interface edition boasts eSATA and USB 2.0. Each version is available in 1TB, 1.5TB, and 2TB capacities.
The 2big sports a few features that the My Book does not. Its drives are on custom holders for easy removal and replacement. Like the My Book, the system must still be powered down to change drives, as it does not support hot swapping.
LaCie makes a series of spare drives specifically for the 2big, allowing you to keep a spare disk on hand if desired. A key is included with the drive to lock and unlock the removable drives. The key is also used to set the RAID mode. Again, the 2big comes configured as a RAID 0 by default; to change to RAID 1, use the key to change the switch on the back of the unit to “SAFE 100” mode.
For the ultimate in style and performance in RAID 1, look no further than the G-SAFE by the good folks at G-Technology. The only RAID system designed specifically for digital photographers, the G-SAFE can only be configured as a RAID 1. It uses two high-performance 7200rpm SATA II drives, each with up to 32MB of cache memory.
The system is available in 250GB, 500GB, and 1TB capacities. If these sound a bit on the svelte side, have no fear: each capacity represents the available in space in the array's RAID 1 configuration; there's no need to divide by two to determine the space you'll actually be able to use.
The G-SAFE features two hot-swappable drive modules, a dual USB 2.0 and FireWire-800 interface, and a front-panel LCD that displays the array's health status. For further peace of mind, the array features an audible alarm that sounds when one of the disks has failed. This prompts you to take immediate action to replace the failed disk. G-Technology offers a series of spare disks just for this purpose. Once a failed disk is replaced, the array will automatically rebuild itself into a RAID 1 by copying data to the new disk.
There are a few options available to help photographers protect their data. Using a RAID to protect data in real time is only one aspect of maintaining a healthy backup regimen. Offsite data storage, archival-quality optical discs, and online backup services should also be utilized in order to fully protect data.
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