The continuing trend towards higher capacity hard drives with lower prices is causing more and more decision-makers to ask themselves whether tape drives really make sense for backup. Streaming tape drives, also called "streamers," have some disadvantages. Handling is relatively fiddly, and in the case of a drive defect, a matching spare part must be obtained before the drive can be used again.

Even a cursory Internet search yields repeated horror stories that users have already suffered. DLT volumes, for example, can be pulled far out of the cartridge, placing a great strain on the tape material. With DAT tapes, reports have surfaced again and again of tapes which cannot be read by all drives. In short: you can't simply trust that your backup tapes will work when you need them. To make backups really safe, you need care, attention and detailed planning - right up to testing for an emergency.

Hard drives for backup can be handled differently, since these days Universal Serial Bus (USB) and FireWire makes for easy installation internally or via external cabling. A 200 GB drive can now be had in stores for less than $100. Even drives that manufacturers have approved for continuous operation cost not much more. Of course, it must be pointed out, with no shadow of a doubt: a single hard drive will never count as a secure backup medium. The risk of a defect (mechanical or electronic) is simply too great.

Hence, the only hard drive products that can be considered a reasonable backup solution are those that write data to more than just one drive, or to more than several in more complex networks. The ARAID M100 from Accordance combines two 2.5" hard drives in a compact storage system for 5.25" drive slots. Highly Reliable Systems sent us a simple, USB 2.0-based 19" system for up to seven hard drives. Iomega's REV drive has been on shelves for about a year and entered this test in its external SCSI version. Last but not least, StorCase sent us removable hard drive systems for 2.5" and 3.5" to check out.