In my Times column Thursday, I wrote about the Drobo, a consumer version of the RAID storage units that are popular in corporate IT departments.
The Drobo's “Beyond RAID†technology gives you a lot more flexibility than regular RAID systems. Most of those require you to install multiple drives of the same type, speed and capacity. Most of those require reformatting and recopying if one of the drives fails. Most of those require serious technical skills to work.
The Drobo, by contrast, is far more flexible and almost automatic.
Some of the reader feedback includes good questions - and a further education on what RAID is and isn't; I thought I'd share the best of i t here.
Q: What about online back-up services like Mozy and Carbonite? Those seem like better solutions, since they're not subject to risk of fire or theft from your office.
A: The big difference is that a Drobo isn't just a backup system; it's a storage system. It's connected to your computer like a huge, huge hard drive, so you can can actually use your data: open and save files, edit videos and so on. Online services are strictly for file recovery.
Online services also require a monthly fee forever-$6 to $12 a month. And should the worst come to pass, it can take days or weeks to download your files again.
That's not to knock online backup services; they're great for a lot of people. They're just not the same thing.
Q: You did a good job educating people on the different connection types (Thunderbolt, USB 3, and so on) and hard drive types (hard drive, SSD). But you might as well take the next step and explain some differences in classes of hard drives.
You mention that a 2-terrabyte drive can be purchased for $110, but that is likely one of the green models from WD or Seagate. If you're going to drop the cash on something like a Drobo for a real backup solution, you should go up to a longer lasting, server-grade drive (WD Red, WD RE series, Seagate Constellation). At 1TB for $90, 2TB at $160, you will get lower power consumption, lower temperatures, higher MTBF (mean time between failures), and a 3-year warranty for drives designed for 24 x 7 operation.
A: Fantastic suggestion.
Q: I am sure you are already getting many e-mails like this one. A RAID system is not a backup solution, per se. If you overwrite or change a file, it automatically gets changed on the RAID drives. A bad, deleted, or corrupted files get replicated across the RAID system. There is no way to restore an old file without a separate backup solution.
A: Weird. In my terminology, a “backup†is a duplicate of your fi les - I didn't know that it implied “versioning†(rewinding a file to an earlier state). Maybe that's the techie's use of the term?
In any case, the Drobo does work with, for example, the Time Machine feature of a Mac, which offers versioning.
(Just a note about that, though: Time Machine likes to have a whole hard drive to itself. So using Time Machine with the Drobo requires extra setup steps and less convenience; details are here.)
Q: Your article erroneously refers to RAID as a backup device. If your offices burn down in a fire, drown in a flood, or get robbed by a thief, you lose all your data.
A: Good point. Or, as I wrote in the column, “Any storage or backup that's right there in your home or office is vulnerable to fire, flood or thieves.â€
If you're really serious, you'll back up your backup with online storage.
Q: Last year, I got fed up with adding yet another hard drive, and looked into different systems. I researched t he NAS (network-attached storage) world and found a company called Synology.
It's an even more versatile option for most families, with a very simple Mac or PC setup. I can access all my files over the Internet, adding a VPN feature to encrypt my communication while at a public hotspot. Not only do I have the drive redundancy, but I have my own personal cloud (they have even added a Dropbox-like sync feature, although it's still too buggy to be reliable).
A: Several readers mentioned Synology. Several also recommended the Promise Pegasus RAID systems, which are also expensive but also offer Thunderbolt connections.
Thanks, readers, for the fascinating instruction in the finer points of RAID. The biggest lesson of all, though, is that in this age of ballooning photo, music and video collections, hard-core, huge-capacity storage is no longer a subject only for corporate network administrators. Normal people should start tuning in, too.
