How to configure a cheap, secure RAID backup system for your Mac

“We usually store our photos, documents, and more on a single hard disk — or, increasingly these days, a solid state drive (SSD) — but there’s always the nagging worry that the disk will fail, taking all your work and memories with it,” Christopher Phin writes for Macworld. “Backing up using Time Machine, Super Duper!, or CrashPlan, say, is a good way of reducing this risk, but there is another: RAID.”

“RAID can be incredibly complicated, but it’s extremely worthwhile — one of the things it can do is to mirror the contents of one disk completely to another, all the time,” Phin writes. “While cloning your hard disk using Super Duper!, for example, is something that might happen once a day, with a RAID system, every bit of data that’s written to one disk is simultaneously written to the second, so that if one drive fails, you have a perfect copy of everything it contained on the second. (And optionally, if you replace the failed drive, everything will be mirrored back across to it automatically.)”

“The especially good news is that a mirrored RAID setup like this, once it’s configured, appears to you and to your computer as a single disk, so it’s as easy to use as a single disk—defining it as a backup target, say, or simply dropping files onto it like with any other disk—but just safer,” Phin writes. “You could use a mirrored RAID system like this to store important archives or current work projects, or you could give yourself extra protection against lost data by using a mirrored RAID drive as the one you back up to using, for example, Time Machine. That way, you’re backing up, but your backup itself is doubly protected against failure. This is what we’ll be doing here, but you can use a mirrored RAID disk for anything you like that requires a bit more data security.”

Step-bystep instructions in the full article – recommendedhere.

MacDailyNews Take: Better safe than sorry!


  1. All fine and dandy, but if your house burns down to the ground, what then ?
    Does anyone store offsite backup ?
    When your “Life” is in a good part stored in your computer, offsite backup storage makes a lot of sense.
    I rotate a backup disk of sparseimage files of all my home computers, on a regular basis.
    Better safe than sorry!

    1. If we compare the new reality (photos and other memories on computer hard disks) to the ways this was done before (physical photos and other stuff in boxes / albums), redundant backups elevate the preservation level of digital data to more-or-less the same level as those physical versions. Off-site redundant back up would elevate it to the highest possible level, but realistically, it isn’t quite feasible for majority of non-tech people.

      1. Agree. But I might add that I have a few very-tech friends that don’t do backups period. Guess they are lucky … so far.
        Did try many times to convince them.
        Lazy, irresponsible; hey its their data.

      2. A reasonably computer-savvy person can probably manage something like Crashplan or Backblaze. Then again, even better would be for Apple to make Time Machine in iCloud, but have it work as reliably and clearly as iCloud Photo Library, instead of the toxic hellstew of Apple/iTunes Music.

  2. I’m not as diligent as I would like (who is?), but my main “drive” is my thumb drive in my pocket. Most of what I work on gets moved so much between multiple home computers and work and church that the USB drive makes the most sense. I copy to the machine I’m working on, work it, then “back it up” to the thumb drive to be ready wherever I may decide to work on it again. This technically makes the actual computers at all of those different locations my backups to the thumb drive. Sure, those fail, too, but it wouldn’t take me long to recover it all from those various other locations.

    FAR from standard, and unique to my situation, but might be useful to someone.

    Work files are a different matter entirely. Duplicate external drives to back up, rotated in storage in a safety deposit box. Still not as diligent as I should be, but theoretically backed up weekly, which honestly isn’t enough. We’ve been talking about going RAID of some form so the weekly backup *will* be sufficient.

  3. Repeat after me – RAID IS NOT A BACKUP. Perhaps MacWorld should be more invested in a system expert rather than whomever they used. RAID has one purpose – to increase up time for storage systems. That’s all.

    All the RAID drives in the world won’t help you when Windows or yes even OS X messes up a HFS or NTFS directory. Or when a rouge application erases files. Or when YOU erase a file accidentally.

    If I was going to chose where to spend a limited amount of money, secure backup would come first before any RAID. I’d have at a minimum an external drive with Time Machine but ideally I’d have both onsite and offsite backups (using a cloud service).

    Then and only then would I consider adding a RAID array to increase speed and to prevent down time due to a single drive failure.

    1. Right on!

      A real time backup is fine until corruption enters your boot drive in which case it is PERFECTLY COPIED CORRUPTION to RAID.

      You need both RAID and Carbon Copy Cloner/Super Duper clones, and clones which are rotated offsite.

      High value content means you rotate out RAID sets. Sounds time consuming, but all it means is a small cloth device case holding two hard drives which is tiny if you are using 500 meg 2.5″ HDs.

  4. I’ve been using Drobo for a raid solution for the past two years or so. The concept of having a huge drive with protection against the failure of one or more HDDs in the array is very appealing. I have at least 8 terabytes of movies and music and old files I’d like to keep. Good for my large iTunes library. Anyway….my Drobo power supply has failed twice since I’ve had it and since it is out of warranty, my option is to purchase another…or find a different solution to address my needs. I’d love informed suggestions from folks on this forum. Drobo also has thunderbolt and an SSD as the initial drive it reads to for speedy transfer…but the fact that it has failed me twice in a short period of time and the company won’t stand behind their product has left me cold on them. Anyone have other advice?

    1. I use Akitio Systems, Hydra connected via Thunderdock2 & eSATA. I run a RAID 5 with four (5TB) hard drives. I’d rather run a RAID 6 but all in all it provides a nice backup for my 7TB’s of iTunes Data and the 3TB’s of Drone footage and the 2.5TB Fusion boot drive.

    1. My Drobo Pro has iSCSi, FireWire and USB 2.0.

      They dropped software support for iSCSi and FireWire fails in the middle of large backups. Only USB works, and is the slowest of the three.

      Drobo sucks!

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