Dell's New Reliability

by Bob Seidel

Dell has announced a new function on some of its PCs called "DataSafe". There has been some industry hoopla about it, so I thought I would try to explain what it means to you. Unfortunately, I couldn't find anything at all about DataSafe on the Dell website so I am working from press releases only, but the information is general and relevant to other PCs, so let's dive in.

DataSafe seems to combine two data backup technologies that have been around for years. The first is RAID configured hard drives, and the second is a program to automatically backup an entire hard drive. The program Dell uses for this is a version of the "Ghost" program from Symantec.

RAID configurations of hard drives have been around for about 20 years. The idea was to create storage arrays that were as good as the large (and expensive) mainframe storage devices but at a lower cost. Capacity, performance, and reliability were the goals of RAID. But there are a number of different types of RAID configurations, some offering one or more of those three attributes. RAID 0, called striping, yields better performance by spreading your data over two physical hard drives. This yields higher storage capacity since the two drives appear as one drive with the total storage available - thus two 80GB hard drives in a RAID 0 configuration look like one 160GB hard drive to Windows. But there is no increase in reliability or security - if one drive fails, you still lose your data.

RAID 1, called mirroring, copies everything that goes to one hard drive to a second hard drive. This is done in hardware, is almost instantaneous, and is transparent to the operating system and the user. RAID 1 gives you better reliability in case one drive fails (you just use the other), but no increase in performance or capacity. Other RAID configurations offer more, but are not commonly available for PCs. It appears that Dell is offering RAID 1 on some of its PCs as a component of DataSafe.

Working quite differently are programs like Ghost. Ghost automatically copies the data from one hard drive to another, but does it on a delayed basis in software. If you accidentally erase a file in a RAID 1 configuration, the file is almost instantaneously erased from both. But if you use a program like Ghost to backup, the data is not copied instantaneously, giving you time to recover the file from the backup. Program like Ghost also sometimes keep multiple copies of files in case you have to retrieve an earlier version.

We'll see where Dell goes with this product, but in the mean time you can still get similar benefits yourself. You can purchase a second hard drive and adapter card for your PC that will support RAID, and you can always buy a Ghost-like program. If you do like the Ghost approach, it would be better to backup to an external USB or FireWire hard drive; in case of emergency they are much easier to disconnect and take with you instead of an internal second drive.

What do I do? My main PC uses RAID 0, because I wanted the higher performance. I don't use Ghost, but I do use a program called Second Copy 2000 (available from to automatically copy my critical files through my home network to my wife's PC, and vice-versa. But I also back up on CDs, on an external hard drive, and to the Internet. I am just backup paranoid, I guess!

(Bob Seidel is a local computer consultant in the Southport - Oak Island area. You can visit his Website at or e-mail questions or column ideas to him at For specific inquiries, please call Bob Seidel Consulting, LLC at 278-1007.)