Reliable External Data Storage

Rather than buying consumer external drives as and when you need them, it’s better and cheaper in the long run to get a dedicated multi-disk box of one form or another because it usually has a better build quality, much better power supply components, fan cooling and of course requires far fewer wires to connect it up.

These days I prefer JBOD enclosures such as the Sonnet Fusion and Wiebetech RTX ranges coupled with SoftRAID drive formatting rather than dedicated RAID 3 or 5 enclosures (or hardware RAID 0 devices such as the Drobo), for the following reasons:
  • the JBOD enclosure/HD combination is now cheaper than a dedicated RAID system
  • it's quick and easy to replace any or all of the disks in the enclosure, which effectively turns it into the operational equivalent of an optical drive
  • SoftRAID can be used to format individual disks and create RAID 1 mirrors or RAID 0 stripe volumes
  • SoftRAID monitors disk I/O and will warn you of any I/O errors, which are indicative of faulty disk hardware
  • the SoftRAID driver is preinstalled on every OS X Mac
  • disks are formatted in the standard Apple disk format, unlike hardware RAID systems which tend to write to their disks in a proprietary way unique to each RAID controller card. Consequently, and unlike a hardware RAID system,
  • it's possible to take disks from a JBOD and put them into another one, or into a G5 or Mac Pro, or a FireWire enclosure, or even to connect them directly with a USB - SATA adapter and still get access to your data. I've done this. Whereas,
  • recovering data from a failed hardware RAID system usually requires you to find an identical RAID controller and attach your disks to it. This can be difficult and expensive.
  • Using ChronoSync or similar and an extra pair of disks it's easy to create a second backup of your primary data volumes to keep off-site.
  • An enclosure such as this makes an ideal backup destination for Mac OS X 10.5 Leopard's Time Machine.
I recommend as a basic, cost-effective building block one Sonnet Fusion D400Q plus two spare trays and six disks or one Wiebetech RTX200H-QJ and three disks. Define two of the disks as primary data volumes, each having two backup disks. Two backups live in the Sonnet, the other two are kept offsite. The backup disks are revolved weekly. A ChronoSync backup job keeps everything up to date. I've set up many clients in this way and the system works well.

Mobile Hard Disks

Always keep an up-to-date clone of your portable Mac’s internal hard disk on a mobile disk that you can boot from. Make the clone with SuperDuper! or Carbon Copy Cloner. Not all mobile disks can boot a Mac; it depends on the type of FireWire bridge chip installed in the disk enclosure. Light, cheap mobile hard disks are good to have on location for backing up to and mailing home periodically on a long shoot.